ANALOG SIGNAL RECORDING AND PLAYBACK METHOD AND SYSTEM

• US 3,745,264 A
• Filed: 07/23/1970
• Issued: 07/10/1973
• Est. Priority Date: 07/23/1970
• Status: Expired due to Term

• Current Assignee: Emerson S. Thomas, Richard J. Sutter, Simpson W. Dwain
• Original Assignee: Emerson S. Thomas, Richard J. Sutter, Simpson W. Dwain
• Inventors: Emerson, S. Thomas, Simpson, W. Dwain, Sutter, Richard J.
• Primary Examiner(s): Goudeau, J. Russell
• Application Number:
  US05/057,489
• Time in Patent Office: 1,083 Days
• Field of Search: 179/1SA,15A,1.2MD 340/174.1C,174.1G,174.1H,174.1P,152
• US Class Current: 360/12
• CPC Class Codes: G06F 3/16 Sound input; Sound output speech processing G10L

Abstract

Apparatus and method for recording and reproducing analog signals. When used in a voice response system, audio signals are sampled at approximately a 5 kHz rate, and the samples are recorded on the track of a magnetic disc or drum. The record medium makes a single rotation in less time than it takes to record or reproduce a word. Thus, the samples are recorded in an interlaced format on the record medium. By storing samples only, much less storage capacity is needed for each signal than in the case where the continuous signal is recorded. The interlacing technique allows fast random access to any signal and does not require the use of buffering circuits. The samples are recorded in the form of pulse widths to provide extremely dense packing of information.

Claims

1. A system for recording and reproducing analog signals comprising a record medium, means for recording items of data on said record medium, means for reading items of data on said record medium, means for continuously moving said record medium at a speed such that each of successive passes of said record medium takes place in a time interval substantially shorter than the duration of a typical analog signal to be recordeD on or reproduced from said record medium, means for periodically sampling the analog signal to be recorded at a rate sufficient to enable the proper reconstruction thereof, means for controlling said recording means in response to signals from said reading means to record items of data on said record medium representative of temporally successive samples of the analog signal taken by said sampling means while said record medium moves, all of the items of data representative of temporally successive samples of the analog signal being recorded in an interlaced format on said record medium during successive passes of said record medium by said recording means, means for controlling the retrieval of items of data read from said record medium by said reading means in the same temporal sequence in which the items of data represent temporally successive samples of the analog signal, and means for reconstructing the analog signal from the retrieved items of data.

2. periodically sampling each analog signal to be recorded at a rate sufficient to enable the proper reconstruction thereof,

3. A system for recording and reproducing analog signals in accordance with claim 2 further including means for initiating the operation of said sampling means responsive to the passing of all items of data already recorded in any segment by said recording means.

4. registering the positions on said record medium of the items of data included in each independently retrievable group contained in said interlaced format.

5. A system for recording and reproducing analog signals in accordance with claim 2 wherein said retrieval controlling means includes register means for identifying the same positioned item of data in each segment of said record medium during any pass of said record medium by said reading means, means for retrieving the identified item of data in each segment as the segment passes by said reading means, and means for governing said register means to identify successively positioned items of data during successive passes of said record medium by said reading means.

6. A system for recording and reproducing analog signals in accordance with claim 5 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample taken by said sampling means, and said reconstructing means includes means for converting the width of each pulse retrieved from said record medium to a signal level and means for smoothing successive signal levels.

7. A system for recording and reproducing analog signals in accordance with claim 2 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample taken by said sampling means.

8. A system for recording and reproducing analog signals in accordance with claim 2 wherein said record controlling means causes items of data representative of samples of each analog signal to be recorded in an interlaced format on said record medium with groups of items of data representative of samples of different analog signals being similarly recorded in an interlaced format on said record medium.

9. A system for recording and reproducing analog signals in accordance with claim 8 wherein all of the same-positioned items of data in said segments constitute an information stream with successive iNformation streams being identified by a numerical sequence determined by the order in which the items of data constituting the information streams were recorded, and said retrieval controlling means includes means for identifying a group of successively numbered information streams containing the samples of a selected signal and means for retrieving successive items of data from all of the identified information streams in numerical sequence.

10. A system for recording and reproducing analog signals in accordance with claim 1 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample taken by said sampling means.

11. A system for recording and reproducing analog signals in accordance with claim 10 wherein said record controlling means causes items of data representative of samples of each analog signal to be recorded in an interlaced format on said record medium with groups of items of data representative of samples of different analog signals being similarly recorded in an interlaced format on said record medium.

12. A system for recording and reproducing analog signals in accordance with claim 10 wherein said analog signals are audio signals, said sampling frequency is no greater than 30 kHz and each of the successive passes of said record medium takes place in substantially less time than that required to speak a typical word.

13. A system for recording and reproducing analog signals in accordance with claim 1 wherein said record controlling means causes items of data representative of samples of each analog signal to be recorded in an interlaced format on said record medium with groups of items of data representative of samples of different analog signals being similarly recorded in an interlaced format on said record medium.

14. A system for recording and reproducing analog signals in accordance with claim 13 wherein said analog signals are audio signals, said sampling frequency is no greater than 30 kHz and each of the successive passes of said record medium takes place in substantially less time that that required to speak a typical word.

15. A system for recording and reproducing analog signals in accordance with claim 1 wherein said record medium is capable of storing two types of signals of opposite polarities, and said record controlling means includes means for initially dividing said record medium into a plurality of segments of opposite polarities, means for controlling the recording of successive opposite polarity pulses in each of said segments with a single pulse being recorded in each segment during each pass of said record medium by said recording means, means for detecting a transition in the polarity of a segment as it passes by said reading means, means for writing a pulse of either polarity on said record medium, means for enabling said writing means to write pulses of alternating polarities as transitions in the polarity of said record medium are detected, and means for turning on said writing means so that it writes a pulse of the polarity in which it has been enabled after all of the previously recorded pulses in a segment have passed by said recording means and another pulse is to be recorded.

16. A system for recording and reproducing analog signals in accordance with claim 1 wherein data is recorded on said record medium in two polarities and said record medium is divided into a plurality of segments of alternating polarities, said record controlling means causes pulses of opposite polarities to be recorded in succession in each segment with the width of each pulse corresponding to the amplitude of the respective sample of the analog signal being recorded, one such pulse being recorded during each pass of any segment by said recording means, said record controlling means includes means coupled to said reading means for counting the number of polarity transitions in each segment as such segment passes by said reading means for determining the time Of operation of said sampling means, said retrieval controlling means includes means for counting the number of polarity transitions in each segment as such segment passes by said reading means to determine the item of data in each segment to be operated upon during the pass of the segment by said reading means, and said reconstructing means includes means for converting the time interval between the two polarity transitions which define the item of data being operated upon to a signal level and means for smoothing successive signal levels.

17. A system for recording and reproducing analog signals in accordance with claim 16 wherein all of the same-positioned pulses in said segments constitute an information stream, with successive information streams being identified by a numerical sequence determined by the order in which the items of data constituting the information streams were recorded, and said retrieval controlling means includes means for identifying a group of successively numbered information streams containing the samples of a selected signal to control the retrieval of successive pulses from all of the identified information streams in numerical sequence.

18. A system for recording and reproducing analog signals in accordance with claim 17 wherein said record controlling means includes means for identifying the information streams corresponding to any analog signal recorded on said record medium.

19. A system for recording and reproducing analog signals in accordance with claim 1 wherein said record medium is divided into a plurality of segments, said record controlling means causes items of data representative of temporally successive samples to be recorded in successive segments during each pass of said record medium by said recording means with successive items of data in each segment being recorded one after the other in the same order as the respective samples are taken during successive passes of such segments by said recording means, all of the same-positioned items of data in said segments constituting an information stream with all of the information streams being ordered in accordance with the sequence in which the items of data therein were recorded, and said retrieval controlling means includes means for identifying a single information stream during each pass of said record medium by said reading means, means for counting the items of data in each segment as such segment passes by said reading means until a selected item of data is reached which is contained within the identified information stream, means for operating upon such selected item of data, means for changing the identified information stream following each pass of said record medium by said reading means, and means for inhibiting the operation of said retrieval controlling means after all of the information streams containing items of data of the analog signal to be reproduced have been identified by said identifying means and the items of data therein have been operated upon.

20. A system for recording and reproducing analog signals in accordance with claim 19 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample taken by said sampling means and said sampling rate varies from segment to segment in accordance with the sum of all pulse widths in successive segments.

21. A system for recording and reproducing analog signals in accordance with claim 1 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample taken by said sampling means and said sampling rate varies from segment to segment in accordance with the sum of all pulse widths in successive segments.

22. A system for recording and reproducing analog signals in accordance with claim 21 wherein said recording controlling means controls a pulse to be recorded on said record medium for every sample taken by said sampling means, the width of each pulse varying betweEn a maximum value and a non-zero minimum value.

23. A system for recording and reproducing analog signals in accordance with claim 22 further including means for translating each analog signal to be recorded so that it is of constant polarity and has a non-zero minimum value.

24. A system for recording and reproducing analog signals in accordance with claim 1 wherein said record controlling means causes said record medium to be divided into a plurality of segments with a single item of data representative of a sample being recorded in sequence in each of said segments as said segments pass by said recording means with successive items of data in each segment being recorded one after the other in the same order as the respective samples are taken during successive passes of such segment by said recording means, said items of data being in the form of pulses on said record medium, and means for controlling the writing of a pulse on said record medium which is distinguishable from all pulses representative of samples in front of the first segment on said record medium to identify the start of a new pass of said record medium by said recording means.

25. A system for recording and reproducing analog signals in accordance with claim 24 wherein said record controlling means controls the recording of a pulse at the end of each segment which is distinguishable from all other types of pulses recorded on said record medium to identify the end of the passing of each segment by said recording means.

26. A system for recording and reproducing analog signals in accordance with claim 1 wherein said record medium is divided into a plurality of segments and said record controlling means causes items of data representative of temporally successive samples to be recorded in successive segments during each pass of said record medium by said recording means with successive items of data in each segment being recorded one after the other in the same order as the respective samples are taken during successive passes of such segment by said recording means, all of the same-positioned items of data in said segments constituting an information stream, and said retrieval controlling means includes a plurality of decoders, means for extending said reading means to each of said decoders, and signal select control means for extending to each of said decoders data representative of a particular sequence of information streams to selectively control the reproduction by each of said decoders of a respective analog signal, each of said decoders including means for retrieving only the items of data included in the respective identified information streams.

27. A system for recording and reproducing analog signals in accordance with claim 26 further including means extended between each of said decoders and said signal select control means for indicating to said signal select control means that such decoder is reproducing an analog signal.

28. A system for recording and reproducing analog signals in accordance with claim 27 wherein said record medium includes a plurality of tracks, said reading means includes a plurality of means for reading from each of said tracks, said signal elect control means includes means for identifying a particular track to be operated upon by each of said decoders, and each of said decoders includes means for limiting operations to data read from the respective identified track.

29. A system for recording items of data representative of samples of at least two separately recognizable analog signals on a record medium such that temporally successive represented samples of analog signals to be reproduced therefrom are represented in an interlaced format, each of said analog signals having samples which are to be independently retrievable as a group without the others from said record medium, comprising means for recording items of data on said record medium, means for continuously moving said record medium past said recording means at a speed such that each of sUccessive passes of said record medium by said recording means takes place in a time interval substantially shorter than the duration of a typical analog signal whose respective samples are to be recorded on said record medium, means for periodically sampling an analog signal to be recorded at a rate sufficient to enable the proper reconstruction thereof, means for controlling said recording means to record items of data on said record medium representative of temporally successive samples taken by said sampling means, all of the items of data representative of temporally successive samples of each analog signal being recorded in an interlaced format on said record medium with groups of items of data representative of samples of different analog signals being recorded in an interlaced format on said record medium, and means for representing the positions on said record medium of the items of data included in each independently retrievable group contained in said interlaced format.

30. A system for recording analog signals in accordance with claim 29 wherein each of said separately recognizable analog signals is the representation of a respective speech component.

31. A system for recording analog signals in accordance with claim 29 wherein said record medium is divided into a plurality of segments and said record controlling means causes items of data representative of temporally successive samples to be recorded in successive segments during each pass of said record medium by said recording means with successive items of data in each segment being recorded one after the other in the same order as the respective samples are taken during successive passes of such segment by said recording means.

32. A system for recording analog signals in accordance with claim 31 further including means for initiating the operation of said sampling means responsive to the passing of all items of data already recorded in any segment by said recording means.

33. A system for recording analog signals in accordance with claim 31 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample taken by said sampling means.

34. A system for recording analog signals in accordance with claim 29 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample taken by said sampling means.

35. A system for recording analog signals in accordance with claim 34 wherein said analog signals are audio signals, said sampling frequency is no greater than 30 kHz and each of the successive passes of said record medium by said recording means takes place in substantially less time than that required to speak a typical word.

36. A system for recording analog signals in accordance with claim 29 wherein said analog signals are audio signals, said sampling frequency is no greater than 30 kHz and each of the successive passes of said record medium by said recording means takes place in substantially less time than that required to speak a typical word.

37. A system for recording analog signals in accordance with claim 29 wherein data is recorded on said record medium in two polarities and said record medium is divided into a plurality of segments of alternating polarities, said record controlling means causes pulses of opposite polarities to be recorded in succession in each segment with the width of each pulse corresponding to the amplitude of the respective sample of the analog signal being recorded, one such pulse being recorded during each pass of any segment by said recording means, and said record controlling means includes means coupled to said recording means for counting the number of polarity transitions in each segment as such segment passes by said recording means for determining the time of operation of said sampling means.

38. A system for recording analog signals in accordance with claim 37 wherein all of the same-poSitioned pulses in said segments constitute an information stream, and further including means for identifying successive information streams by a numerical sequence determined by the order in which the items of data constituting the information streams are recorded.

39. A system for recording analog signals in accordance with claim 29 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample taken by said sampling means and said sampling rate varies from segment to segment in accordance with the sum of all pulse widths previously recorded in successive segments.

40. A system for recording analog signals in accordance with claim 39 wherein said record controlling means controls a pulse to be recorded on said record medium for every sample taken by said sampling means, the width of each pulse varying between a maximum value and a non-zero minimum value.

41. A system for recording analog signals in accordance with claim 40 further including means for translating each analog signal to be recorded so that it is of constant polarity and has a non-zero minimum value.

42. A system for recording analog signals in accordance with claim 29 wherein said record medium is capable of storing two types of signals of opposite polarities, and said record controlling means includes means for initially dividing said record medium into a plurality of segments of opposite polarities, means for controlling the recording of successive opposite polarity pulses in each of said segments with a single pulse being recorded in each segment during each pass of said record medium by said recording means, means for detecting a transition in the polarity of a segment as it passes by said recording means, means for writing a pulse of either polarity on said record medium, means for enabling said writing means to write pulses of alternating polarities as transitions in the polarity of said record medium are detected, and means for turning on said writing means so that it writes a pulse of the polarity in which it has been enabled after all of the previously recorded pulses in a segment have passed by said recording means and another pulse is to be recorded.

43. A system for recording analog signals in accordance with claim 29 wherein said record controlling means causes said record medium to be divided into a plurality of segments with a single item of data representative of a sample being recorded in sequence in each of said segments as said segments pass by said recording means with successive items of data in each segment being recorded one after the other in the same order as the respective samples are taken during successive passes of such segment by said recording means, said items of data being in the form of pulses on said record medium, and means for controlling the writing of a pulse on said record medium which is distinguishable from all pulses representative of samples in front of the first segment on said record medium to identify the start of a new pass of said record medium by said recording means.

44. A system for recording analog signals in accordance with claim 43 wherein said record controlling means controls the recording of a pulse at the end of each segment which is distinguishable from all other types of pulses recorded on said record medium to identify the end of the passing of each segment by said recording means.

45. A system for reproducing analog signals comprising a record medium having items of data recorded thereon, all of the items of data being representative of samples of analog signals and being recorded in an interlaced format on said record medium, reading means, means for continuously moving said record medium past said reading means at a speed such that each of successive passes of said record medium by said reading means takes place in a time interval shorter than the duration of a typical analog signal to be reproduced from said record medium, means for controlling the pEriodic retrieval of less than all of the items of data in said interlaced format read from said record medium by said reading means during multiple passes of said record medium by said reading means in a sequence corresponding to the temporally successive samples of a selected analog signal to be reproduced, and means for reconstructing the selected analog signal from the retrieved items of data.

46. A system for reproducing analog signals in accordance with claim 45 wherein said record medium is divided into a plurality of segments and said items of data representative of successive samples are retrieved from successive segments during each pass of said record medium by said reading means with successive items of data in each segment being retrieved during successive passes of such segment by said reading means, all of the same-positioned items of data in said segments constituting an information stream, and said retrieval controlling means includes a plurality of decoders, means for extending said reading means to each of said decoders, and signal select control means for extending to each of said decoders data representative of a particular sequence of information streams to selectively control the reproduction by each of said decoders of a respective analog signal, each of said decoders including means for retrieving only the items of data included in the respective identified information streams.

47. A system for reproducing analog signals in accordance with claim 46 further including means extended between each of said decoders and said signal select control means for indicating to said signal select control means that such decoder is reproducing an analog signal.

48. A system for reproducing analog signals in accordance with claim 47 wherein said record medium includes a plurality of tracks, said reading means includes a plurality of means for reading from each of said tracks, said signal select control means includes means for identifying a particular track to be operated upon by each of said decoders, and each of said decoders includes means for limiting operations to data read from the respective identified track.

49. A system for reproducing analog signals in accordance with claim 45 wherein said analog signals are audio signals, said retrieval controlling means controls the retrieval of items of data at a rate no greater than 30 kHz and each of the successive passes of said record medium by said reading means takes place in substantially less time than that required to speak a typical word.

50. A system for reproducing analog signals in accordance with claim 45 wherein said record medium is divided into a plurality of segments and successive items of data representative of temporally successive samples of an analog signal are recorded in successive segments of said record medium with successive items of data in each segment following each other in the same order as the respective samples of the analog signal.

51. A system for reproducing analog signals in accordance with claim 50 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample.

52. A system for reproducing analog signals in accordance with claim 50 wherein said retrieval controlling means includes register means for identifying the same-positioned item of data in each segment of said record medium during any pass of said record medium by said reading means, means for retrieving the identified item of data in each segment as the segment passes by said reading means, and means for governing said register means to identify successively positioned items of data during successive passes of said record medium by said reading means.

53. A system for reproducing analog signals in accordance with claim 50 wherein the items of data representative of samples of each analog signal are recorded in an interlaced format on said record medium with groups of items of data representative of samples of different analog signals being similarly recorded in an interlaced format on said record medium.

54. A system for reproducing analog signals in accordance with claim 53 wherein all of the same-positioned items of data in said segments constitute an information stream with successive information streams being identified by a numerical sequence determined by the order in which the items of data constituting the information streams represent sequential samples, said retrieval controlling means includes means for identifying a group of successively numbered information streams containing the samples of a selected signal and said retrieving means retrieves successive items of data from all of the identified information streams in numerical sequence.

55. A system for reproducing analog signals in accordance with claim 45 wherein said record medium is divided into a plurality of segments with a single item of data representative of a sample being retrieved in sequence from each of said segments as said segments pass by said reading means with successive items of data in each segment being retrieved during successive passes of such segment by said reading means, and further including a pulse recorded on said record medium which is distinguishable from all pulses representative of samples in front of the first segment on said record medium to identify the start of a new pass of said record medium by said reading means.

56. A system for reproducing analog signals in accordance with claim 55 wherein a pulse is recorded on said record medium at the end of each segment, which pulse is distinguishable from all other types of pulses recorded on said record medium to identify the end of the passing of each segment by said reading means.

57. A system for reproducing analog signals in accordance with claim 45 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample.

58. A system for reproducing analog signals in accordance with claim 57 wherein the items of data representative of samples of each analog signal are recorded in an interlaced format on said record medium with groups of items of data representative of samples of different analog signals being similarly recorded in an interlaced format on said record medium.

59. A system for reproducing analog signals in accordance with claim 45 wherein the items of data representative of samples of each analog signal are recorded in an interlaced format on said record medium with groups of items of data representative of samples of different analog signals being similarly recorded in an interlaced format on said record medium.

60. A system for reproducing analog signals in accordance with claim 59 wherein said analog signals are audio signals, said retrieval controlling means controls the retrieval of items of data at a rate no greater than 30 kHz and each of the successive passes of said record medium by said reading means takes place in substantially less time than that required to speak a typical word.

61. A system for reproducing analog signals in accordance with claim 45 wherein data is recorded on said record medium in two polarities and said record medium is divided into a plurality of segments with pulses of opposite polarities recorded in succession in each segment and with the width of each pulse corresponding to the amplitude of the respective sample of the analog signal, said retrieval controlling means retrieves one pulse during each pass of any segment by said reading means and includes means for counting the number of polarity transitions in each segment as such segment passes by said reading means to determine the item of data in each segment to be operated upon during the pass of the segment by said reading means, and said reconstructing means includes means for converting the time interval between the two polarity transitions which define the item of data being operated upon to a signal level and means for smoothing successive sIgnal levels.

62. A system for reproducing analog signals in accordance with claim 61 wherein all of the same-positioned pulses in said segments constitute an information stream, with successive information streams being identified by a numerical sequence determined by the order in which the items of data constituting the information streams correspond to successive samples, and said retrieval controlling means includes means for identifying a group of successively numbered information streams containing the samples of a selected signal to control the retrieval of successive pulses from all of the identified information streams in numerical sequence.

63. A system for reproducing analog signals in accordance with claim 45 wherein said record medium is divided into a plurality of segments, items of data representative of temporally successive samples being recorded in successive segments with successive items of data in each segment being recorded one after the other in the same order as the respective samples, all of the same-positioned items of data in said segments constituting an information stream with all of the information streams being ordered in accordance with the sequence in which the items of data correspond to respective sequential samples, and said retrieval controlling means includes means for identifying a single information stream during each pass of said record medium by said reading means, means for counting the items of data in each segment as such segment passes by said reading means until a selected item of data is reached which is contained within the identified information stream, means for operating upon such selected item of data, means for changing the identified information stream following each pass of said record medium by said reading means, and means for inhibiting the operation of said retrieval controlling means after all of the information streams containing items of data of the analog signal to be reproduced have been identified by said identifying means and the items of data therein have been operated upon.

64. A system for reproducing analog signals in accordance with claim 63 wherein the rate at which items of data are retrieved varies from segment to segment in accordance with the sum of all pulse widths in successive segments.

65. A system for reproducing analog signals in accordance with claim 45 wherein the rate at which items of data are retrieved varies from segment to segment in accordance with the sum of all pulse widths in successive segments.

66. A system for reproducing analog signals in accordance with claim 65 wherein the width of each pulse on said record medium varies between a maximum value and a non-zero minimum value.

67. A system for reproducing analog signals in accordance with claim 66 further including means for translating each reconstructed analog signal so that it has an average value of zero.

68. A record medium on which are stored a plurality of samples Aij of an analog signal, where i 1,2,3, . . . N and j 1,2,3, . . . M, and the samples of said analog signal have a time sequence A11, A12, A13, . . . A1M, A21, A22, A23, . . . A2M, A31, A32, A33, . . . A3M, . . . AN1, AN2, AN3, . . . ANM and are stored on the record medium in a spatial sequence A11, A21, A31, . . . AN1, A12, A22, A32, . . . AN2, A13,A23, A33, . . . AN3, . . . A1M, A2M, A3M, . . . ANM, said record medium being characterized in that during normal reading of information therefrom all of the recorded information can be read in a time substantially shorter than the duration of a typical analog signal whose samples are stored therein, and being further characterized in that samples of said analog signal are stored in the form of pulses whose widths are related by a conTinuous function to the amplitude of the analog signal and the trailing edges of substantially all of said pulses are the leading edges of respective succeeding pulses.

69. A record medium in accordance with claim 68 wherein said analog signal is the representation of a speech component.

70. A record medium in accordance with claim 68 wherein said samples are stored in the form of a closed loop with sample A11following sample ANM.

71. A record medium in accordance with claim 70 wherein the same distance on the record medium separates every pair of samples A1j and A1,j 1.

72. A record medium in accordance with claim 70 wherein each sample is stored in one of two states and each spatial sample sequence A1j, A2j, A3j, . . . ANj consists of samples stored in alternating, opposite states.

73. A record medium in accordance with claim 72 wherein the spatial sample sequence A11, A12, A13, . . . A1M consists of samples stored in alternating, opposite states.

74. A record medium in accordance with claim 70 wherein an end-of-pass distinguishing pulse is stored between samples ANM and A11.

75. A record medium in accordance with claim 74 wherein an end-of-segment distinguishing pulse is stored between every pair of successive samples ANj and A1,j 1.

76. A record medium on which are stored a plurality of samples Aij, Bkj of at least two separately recognizable analog signals A and B, where i 1,2,3, . . . N, k 1,2,3, . . . L, and j 1,2,3, . . . M, the samples of analog signal A have a time sequence A11, A12, A13, . . . A1M, A21, A22, A23 . . . A2M, A31, A32, A33, . . . A3M, . . . AN1, AN2, AN3, . . . ANM and the samples of analog signal B have a time sequence B11, B12, B13, . . . B1M, B21, B22, B23, . . . B2M, B31,B32, B33, . . . B3M, . . . BLI, BL2, BL3, . . . BLM, and the samples are stored on the record medium in a spatial sequence A11, A21, A31, . . . AN1, B11, B21, B31, . . . BL1, A12, A22, A32, . . . AN2, B12, B22, B32, . . . BL2, A13, A23, A33, . . . AN3, B13, B23, B33, . . . BL3, . . . A1M, A2M, A3M, . . . ANM, B1M, B2M, B3M, . . . BLM, each of said analog signals having samples which are to be independently read as a group from said record medium, said record medium being characterized in that during normal reading of information therefrom all of the recorded information can be read in a time substantially shorter than the duration of a typical analog signal whose samples are stored therein and being adapted for use with means for reading therefrom the samples in only a selected group independent of the samples in any other group.

77. A record medium in accordance with claim 76 wherein each of said separately recognizable analog signals is the representation of a respective speech component.

78. A record medium in accordance with claim 76 wherein said samples are stored in the form of a closed loop with sample A11 following sample BLM.

79. A record medium in accordance with claim 78 wherein the same distance on the record medium separates every pair of samples A1j and A1,j 1.

80. A record medium in accordance with claim 78 wherein each sample is stored in one of two states and each spatial sample sequence A1j, A2j, A3j, . . . ANj, B1j, B2j, B3j, . . . BLj consists of samples stored In alternating, opposite states.

81. A record medium in accordance with claim 80 wherein the spatial sample sequence A11, A12, A13, . . . A1M consists of samples stored in alternating, opposite states.

82. A record medium in accordance with claim 78 wherein an end-of-pass distinguishing pulse is stored between samples BLM and A11.

83. A record medium in accordance with claim 82 wherein an end-of-segment distinguishing pulse is stored between every pair of successive samples BLj and A1,j 1.

84. A record medium in accordance with claim 83 wherein each of said samples is stored in the form of a pulse whose width corresponds to the amplitude of the respective analog signal.

85. A record medium in accordance with claim 78 wherein each of said samples is stored in the form of a pulse whose width corresponds to the amplitude of the respective analog signal.

86. A record medium in accordance with claim 85 wherein the same distance on the record medium separates every pair of samples A1j and A1,j 1.

87. A record medium in accordance with claim 85 wherein each sample is stored in one of two states and each spatial sample sequence A1j, A2j, A3j, . . . ANj, B1j, B2j, B3j, . . . BLj consists of samples stored in alternating, opposite states.

88. A method for recording on a record medium at least two separately recognizable analog signals, each of said analog signals being characterized in that it is to be independently retrievable from said record medium, comprising the steps of:

89. A method for recording analog signals in accordance with claim 88 wherein said analog signals are audio signals, said sampling frequency is no greater than 30 kHz and each of the successive passes of said record medium takes place in substantially less time than that required to speak a typical word.

90. A method for recording analog signals in accordance with claim 88 wherein each of said separately recognizable analog signals is the representation of a respective speech component.

91. A method for recording analog signals in accordance with claim 88 wherein each item of data recorded on said record medium in step (1) is a pulse whose width corresponds to the amplitude of the respective sample taken during step (2).

92. A method for recording analog signals in accordance with claim 91 wherein said analog signals are audio signals, said sampling frequency is no greater than 30 kHz and each of the successive passes of said record medium takes place in substantially less time than that required to speak a typical word.

93. A method for recording analog signals in accordance with claim 88 wherein data is recorded on said record medium in two polarities in step (1) and said record medium is divided into a plurality of segments of alternating polarities, pulses of oppoSite polarities being recorded in succession in each segment with the width of each pulse corresponding to the amplitude of the respective sample of the analog signal taken in step (2), one such pulse being recorded during each pass of any segment, and in step (3) the number of polarity transistions in each segment as such segment moves is counted for determining when step (2) is performed.

94. A method for recording analog signals in accordance with claim 93 wherein all of the same-positioned pulses in said segments constitute an information stream, and in step (3) successive information streams are identified by a numerical sequence determined by the order in which the items of data constituting the information streams are recorded.

95. A method for recording analog signals in accordance with claim 88 wherein each item of data recorded on said record medium in step (1) is a pulse whose width corresponds to the amplitude of the respective sample taken by said sampling means in step (2) and said sampling rate varies from segment to segment in accordance with the sum of all pulse widths previously recorded in successive segments.

96. A method for recording analog signals in accordance with claim 95 wherein in step (1) a pulse is recorded on said record medium for every sample taken in step (2), the width of each pulse varying between a maximum value and a non-zero minimum value.

97. A method for recording analog signals in accordance with claim 88 wherein said record medium is divided into a plurality of segments and in step (1) a single item of data representative of a sample is recorded in sequence in each of said segments with successive items of data in each segment being recorded one after the other in the same order as the respective samples are taken in step (2), said items of data being in the form of pulses on said record medium, and further including the step of writing a pulse on said record medium which is distinguishable from all pulses representative of samples in front of the first segment on said record medium to identify the start of a new pass of said record medium.

98. A method for recording analog signals in accordance with claim 97 further including the step of recording a pulse at the end of each segment which is distinguishable from all other types of pulses recorded on said record medium to identify the end of each segment.

99. A method for recording analog signals in accordance with claim 88 wherein said record medium is divided into a plurality of segments and in step (1) items of data representative of temporally successive samples are recorded in successive segments during each pass of said record medium with successive items of data in each segment being recorded one after the other in the same order as the respective samples are taken during successive passes of such segment.

100. A method for recording analog signals in accordance with claim 99 wherein each item of data recorded on said record medium in step (1) is a pulse whose width corresponds to the amplitude of the respective sample taken during step (2).

101. A method for recording analog signals in accordance with claim 99 wherein each sampling operation in step (2) is initiated responsive to the passing of all item of data already recorded in any segment.

102. A method for recording analog signals in accordance with claim 101 wherein in step (3) the amplitude of each sample taken during step (2) is converted to a corresponding pulse width, and each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample.

103. A method for reproducing analog signals from groups of items of data recorded on a record medium, all of the items of data in each group being representative of samples of a respective independently retrievable analog signal and being recorded in an interlaced format on said record medium, with the items of data of all groups being recorded in an interlaced format, comprising the steps Of:

104. A method for reproducing analog signals in accordance with claim 103 wherein said analog signals are audio signals, in step (3) items of data are retrieved at a rate no greater than 30 kHz and in step (1) each successive pass of said record medium takes place in substantially less time than that required to speak a typical word.

105. A method for reproducing analog signals in accordance with claim 103 wherein a plurality of analog signals, either the same or different, can be reproduced simultaneously for extension to different output channels, a respective group of items of data is identified in step (2) for each of said output channels, the items of data in only the respective identified group are retrieved in step (3) for each of said output channels, and in step (4) the respective analog signal is reconstructed for each of said output channels.

106. A method for reproducing analog signals in accordance with claim 105 wherein the respective analog signal for each of said output channels is continuously reconstructed in step (4) as successive items of data in the respective identified group are retrieved in step (3).

107. A method for reproducing analog signals in accordance with claim 103 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample.

108. A method for reproducing analog signals in accordance with claim 107 wherein said analog signals are audio signals, in step (3) items of data are retrieved at a rate no greater than 30 kHz and in step (1) each successive pass of said record medium takes place in substantially less time than that required to speak a typical word.

109. A method for reproducing analog signals in accordance with claim 103 wherein data is recorded on said record medium in two polarities and said record medium is divided into a plurality of segments with pulses of opposite polarities recorded in succession in each segment and with the width of each pulse corresponding to the amplitude of the respective sample of the analog signal, in step (3) one pulse is retrieved during each pass of any segment, step (3) including the sub-step of counting the number of polarity transitions in each segment as such segment moves to determine the item of data in each segment to be operated upon during the pass of the segment, and step (4) includes the sub-steps of converting the time interval between the two polarity transitions which define the item of data being operated upon to a signal level and smoothing successive signal levels.

110. A method for reproducing analog signals in accordance with claim 109 wherein all of the same-positioned pulses in said segments constitute an information stream, with successive information streams being identified by a numerical sequence determined by the order in which the items of data constituting the information streams correspond to successive samples, and in step (3) a group of successively numbered information streams containing the samples of a selected signal are identified to control the retrieval of successive pulses from all of the identified information streams in numerical sequence.

111. A method for reproducing analog signals in accordance with claim 103 wherein said record medium iS divided into a plurality of segments, items of data representative of temporally successive samples are recorded in successive segments with successive items of data in each segment being recorded one after the other in the same order as the respective samples, all of the same-positioned items of data in said segments constituting an information stream with all of the information streams being ordered in accordance with the sequence in which the items of data correspond to respective sequential samples, and step (3) includes the sub-steps of identifying a single information stream during each pass of said record medium, counting the items of data in each segment as such segment moves until a selected item of data is reached which is contained within the identified information stream, operating upon such selected item of data, changing the identified information stream following each pass of said record medium, and inhibiting the retrieval of items of data after all of the information streams containing items of data of the analog signal to be reproduced have been identified and the items of data therein have been operated upon.

112. A method for reproducing analog signals in accordance with claim 111 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample, and the rate at which items of data are retrieved in step (3) varies from segment to segment in accordance with the sum of all pulse widths in successive segments.

113. A method for reproducing analog signals in accordance with claim 103 wherein said record medium is divided into a plurality of segments, in step (3) a single item of data representative of a sample is retrieved in sequence from each of said segments as said segments move with successive items of data in each segment being retrieved during successive passes of such segment, said items of data are in the form of pulses on said record medium, and step (3) includes the sub-step of detecting a pulse recorded on said record medium which is distinguishable from all pulses representative of samples in front of the first segment on said record medium to identify the start of a new pass of said record medium.

114. A method for reproducing analog signals in accordance with claim 113 wherein a pulse is recorded on said record medium at the end of each segment, which pulse is distinguishable from all other types of pulses recorded on said record medium, and step (3) includes the sub-step of detecting such pulses to identify the end of each segment.

115. A method for reproducing analog signals in accordance with claim 113 wherein each independently retrievable analog signal is the representation of a respective speech component.

116. A system for reproducing analog signals in accordance with claim 103 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample, and the rate at which items of data are retrieved in step (3) varies from segment to segment in accordance with the sum of all pulse widths in successive segments.

117. A method for reproducing analog signals in accordance with claim 116 wherein the width of each pulse on said record medium varies between a maximum value and a non-zero minimum value.

118. A method for reproducing analog signals in accordance with claim 117 further including the step of translating each reconstructed analog signal so that it has an average value of zero.

119. A method for reproducing analog signals in accordance with claim 103 wherein each independently retrievable analog signal is the representation of a respective speech component.

120. A method for reproducing analog signals in accordance with claim 119 wherein a plurality of analog signals, either the same or different, can be reproduced simultaneously for extension to different output channels, a respective group of items of data is identified in step (2) for each of said output channels, the iteMs of data in only the respective identified group are retrieved in step (3) for each of said output channels, and in step (4) the respective analog signal is reconstructed for each of said output channels.

121. A method for reproducing analog signals in accordance with claim 120 wherein the respective analog signal for each of said output channels is continuously reconstructed in step (4) as successive items of data in the respective identified group are retrived in step (3).

122. A method for reproducing analog signals in accordance with claim 103 wherein said record medium is divided into a plurality of segments and successive items of data representative of temporally successive samples of an analog signal are recorded in successive segments of said record medium with successive items of data in each segment following each other in the same order as the respective samples of the analog signal.

123. A method for reproducing analog signals in accordance with claim 122 wherein all of the same-positioned items of data in said segments constitute an information stream with successive information streams being identified by a numerical sequence determined by the order in which the items of data constituting the information streams represent sequential samples, and in step (3) a group of successively numbered information streams containing the samples of a selected signal are identified and successive items of data from all of the identified information streams are retrieved in numerical sequence.

124. A method for reproducing analog signals in accordance with claim 122 wherein each item of data recorded on said record medium is a pulse whose width corresponds to the amplitude of the respective sample.

125. A method for reproducing analog signals in accordance with claim 122 wherein step (3) includes the substeps of identifying the same-positioned item of data in each segment of said record medium during any pass of said record medium, retrieving the identified item of data in each segment as the segment moves, and causing successively positioned items of data to be identified during successive passes of said record medium.