Speech synthesis system utilizing variable frame rate

• US 4,441,201 A
• Filed: 01/25/1982
• Issued: 04/03/1984
• Est. Priority Date: 02/04/1980
• Status: Expired due to Fees

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Henderson, Alva E., Wiggins, Richard H.
• Primary Examiner(s): Kemeny, E. S. Matt
• Application Number:
  US06/342,311
• Time in Patent Office: 799 Days
• Field of Search: 179/1 SM, 179/1 SA, 179/1 SD, 179/1 SB, 179/15.55 R, 179/15.55 T, 364/900 MS File, 364/723, 364/724, 340/347 DD, 370/82, 370/84, 370/118, 375/114, 358/261, 381/51, 381/53
• US Class Current: 704/265
• CPC Class Codes: G09B 19/06 Foreign languages with audible presentation of material to be studied G09B5/04
• CPC Class Codes: G10L 19/04 using predictive techniques
• CPC Class Codes: G10L 19/24 Variable rate codecs, e.g. for generating different qualities using a scalable representation such as hierarchical encoding or layered encoding
• CPC Class Codes: G10L 2019/0012 Smoothing of parameters of the decoder interpolation

Abstract

Speech synthesis system implementable in an integrated circuit device capable of converting frames of speech data at a variable frame rate into analog signals representative of human speech. The frames of speech data comprise digital representations of values of pitch, energy, filter coefficients and coded frame rate data. The speech synthesis system includes a linear predictive coding filter as a speech synthesizer which utilizes the speech data at a varying frame rate to produce digital speech signals representative of human speech. Frames of digital speech data including coded frame rate data are received by an input, with the frame rate data being decoded to control both the rate at which the incoming variable-length frames of speech data are accepted by the speech synthesizer and the number of interpolation calculations required to define interpolated speech values between adjacent incoming frames of speech data. A frame control circuit accomplishes the foregoing utilization of speech data at a variable frame rate by the speech synthesizer by providing for a variable number of interpolation calculations between adjacent speech frames from last implemented speech data in which the number of interpolation calculations in a given instance is determined by the frame rate data. A microprocessor controls the access of selected speech data which is stored in a memory. The system also includes a digital-to-analog converter for converting the digital speech signals produced by the filter into analog signals and a speaker for generating audible sounds in the form of synthesized human speech from the analog signals provided by the digital-to-analog converter.

Claims

1. A speech synthesis system comprising:

input means for receiving frames of speech data, said frames of speech data comprising binary representations of pitch data, energy data, reflection coefficient data and coded frame rate data, wherein said coded frame rate data is indicative of a variable time interval between the start of a current frame of speech data and the start of the next successive frame of speech data;

decoding means coupled to said input means for decoding said frame rate data;

interpolator means coupled to said input means and to said decoding means for providing a variable number of interpolation calculations to define interpolated speech values between adjacent frames of speech data from last implemented speech data in which the number of interpolation calculations and the time interval between the respective starts of adjacent frames of speech data in a given instance are determined by said frame rate data;

speech synthesizer means coupled to said interpolator means for selectively converting said frames of speech data and interpolated values thereof into analog speech signals representative of human speech; and

audio means coupled to said speech synthesizer means for converting said analog signals representative of human speech into audible sounds.

2. The speech synthesis system according to claim 1 wherein said audio means comprises a speaker.

3. A speech synthesis system comprising:

input means for receiving frames of speech data including digital speech values and frame rate data indicative of a variable time interval between the start of a current frame of speech data and the start of the next successive frame of speech data;

frame control means coupled to said input means for controlling the rate at which new frames of speech data are received by said input means in response to frame rate data included in a current frame of speech data, the time interval between the receipt of successive new frames of speech data by said input means being variable and being determined by said frame rate data;

interpolator means coupled to said frame control means for providing a variable number of interpolation calculations to define interpolated speech values between adjacent frames of speech data from last implemented speech data in which the number of interpolation calculations in a given instance is determined by said frame rate data;

speech synthesizer means coupled to said input means and to said interpolator means for selectively converting said digital speech values and interpolated values thereof into analog speech signals representative of human speech; and

audio means coupled to said speech synthesizer means for converting said analog signals representative of human speech into audible sounds.

4. The speech synthesis system according to claim 3 wherein said audio means comprises a speaker.

15. The speech synthesis system according to claim 3, wherein the frame rate data included in said frames of speech data is in a coded form, and further including

decoding means coupled to said input means for decoding said frame rate data, said frame control means being coupled to said decoding means as well as to said input means.

5. A speech synthesis system comprising:

memory means for storing selectable speech data, said speech data comprising binary representations of pitch data, energy data, and reflection coefficient data as selectable frames of speech data respectively including coded frame rate data, wherein said coded frame rate data is indicative of a variable time interval between the start of a current frame of speech data and the start of the next successive frame of speech data;

controller means for controlling the selective accessing of said speech data from said memory means;

input means coupled to said memory means for receiving selected frames of speech data as accessed under control of said controller means;

decoding means coupled to said input means for decoding said frame rate data;

frame control means coupled to said decoding means and said input means for controlling the rate at which new frames of speech data are received by said input means in response to frame rate data included in a current frame of speech data, the time interval between the receipt of successive new frames of speech data by said input means being variable and being determined by said frame rate data;

speech synthesizer means coupled to said memory means and responsive to said frames of speech data for generating analog signals representative of human speech; and

audio means coupled to said speech synthesizer means for converting said analog signals representative of human speech into audible sounds.

6. A speech synthesis system comprising:

memory means for storing a plurality of digital speech values indicative of pitch data, energy data, and reflection coefficient data as selectable frames of speech data respectively including coded frame rate data, wherein said coded frame rate data is indicative of a variable time interval between the start of a current frame of speech data and the start of the next successive frame of speech data;

controller means for controlling selective accessing of said plurality of digital speech values from said memory means;

input means coupled to said memory means for receiving selected frames of speech data as accessed under control of said controller means;

decoding means coupled to said input means for decoding said frame rate data;

frame control means coupled to said decoding means and said input means for controlling the rate at which new frames of speech data are received by said input means in response to frame rate data included in a current frame of speech data, the time interval between the receipt of successive new frames of speech data by said input means being variable and being determined by said frame rate data;

interpolator means coupled to said frame control means for providing a variable number of interpolation calculations to define interpolator speech values between adjacent frames of speech data from last implemented speech data in which the number of interpolation calculations in a given instance is determined by said frame rate data;

speech synthesizer means coupled to said input means and to said interpolator means for selectively converting said digital speech values included in the selected frames of speech data and interpolated values thereof into analog speech signals representative of human speech at a data rate determined by said frame rate data; and

audio means coupled to said speech synthesizer means for converting said analog signals representative of human speech into audible sounds.

7. The speech synthesis system according to claim 6, wherein said audio means includes a speaker and amplifier means coupled thereto.

8. The speech synthesis system according to claim 6, further including operator input means for receiving inputs from an operator and coupled to said controller means for controlling said controller means in the selective accessing of said speech data from said memory means.

9. The speech synthesis system according to claim 8, wherein said operator input means comprises a keyboard having a plurality of operator actuatable key switches.

10. The speech synthesis system according to claim 9, wherein said speech synthesis system comprises a portable learning aid.

11. The speech synthesis system according to claim 9, wherein said speech synthesis system comprises a portable calculator device.

12. The speech synthesis system according to claim 9, wherein said speech synthesis system comprises a portable language translator device.

13. A speech synthesis system comprising:

input means for receiving frames of speech data including digital speech values and frame rate data indicative of a variable time interval between the start of a current frame of speech data and the start of the next successive frame of speech data;

interpolator means coupled to said input means for providing a variable number of interpolation calculations to define interpolated speech values between adjacent frames of speech data from last implemented speech data in which the number of interpolation calculations and the time interval between the respective starts of adjacent frames of speech data in a given instance are determined by said frame rate data;

speech synthesizer means coupled to said interpolator means for selectively converting said digital speech values and interpolated values thereof into analog speech signals representative of human speech; and

audio means coupled to said speech synthesizer means for converting said analog signals representative of human speech into audible sounds.

14. The speech synthesis system according to claim 13, wherein the frame rate data included in said frames of speech data is in a coded form, and further including

decoding means coupled to said input means for decoding said frame rate data, said interpolator means being coupled to said decoding means as well as to said input means.

16. The speech synthesis system according to any of claims 13, 14, 3, or 15, wherein the digital speech values included in said frames of speech data are representative of pitch data, energy data, and reflection coefficient data.

17. A speech synthesis system comprising:

means for providing frames of speech data including digital speech values and frame rate data, wherein said frame rate data is indicative of a variable time interval between the start of a current frame of speech data and the start of the next successive frame of speech data;

speech synthesizer means having an input for respectively receiving successive frames of speech data and for selectively converting said digital speech values into analog speech signals representative of human speech;

frame control means responsive to said frame rate data for enabling the acceptance of a new frame of speech data by the input of said speech synthesizer means succeeding the previous frame of speech data, the time interval between the acceptance of successive new frames of speech data by the input of said speech synthesizer means as enabled by said frame control means being variable and being determined by said frame rate data of each frame of speech data, the input of said speech synthesizer means thereby being responsive to said frame control means for respectively receiving successive frames of speech data in variably timed relation to each other; and

audio means coupled to said speech synthesizer means for converting said analog speech signals representative of human speech into audible sounds.

18. The speech synthesizer system according to claim 17, further including interpolator means coupled to said frame control means for providing a variable number of interpolation calculations to define interpolated speech values between successive frames of speech data from last implemented speech data in which the number of interpolation calculations in a given instance is determined by said frame rate data;

and

said speech synthesizer means respectively receiving frames of speech data and interpolated speech values for selectively converting said digital speech values and said interpolated values thereof into said analog speech signals representative of human speech.