Digital voice processing apparatus providing frequency characteristic processing and/or time scale expansion

• US 6,226,605 B1
• Filed: 08/11/1998
• Issued: 05/01/2001
• Est. Priority Date: 08/23/1991
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ikeda, Hiroshi, Nejime, Yoshito, Hotta, Masao
• Primary Examiner(s): Dorvil, Richemond
• Application Number:
  US09/132,214
• Time in Patent Office: 994 Days
• Field of Search: 704/205, 704/207, 704/500, 704/200, 704/210, 704/215, 704/214, 704/208, 704/270, 704/271, 704/501, 704/503
• US Class Current: 704/207
• CPC Class Codes: G10L 21/0232 Processing in the frequency domain
• CPC Class Codes: G10L 21/0364 for improving intelligibility
• CPC Class Codes: G10L 21/04 Time compression or expansion
• CPC Class Codes: H04R 1/005 using digitally weighted transducing elements
• CPC Class Codes: H04R 2205/041 Adaptation of stereophonic signal reproduction for the hearing impaired
• CPC Class Codes: H04R 2225/43 Signal processing in hearing aids to enhance the speech intelligibility
• CPC Class Codes: H04R 25/505 using digital signal processing
• CPC Class Codes: H04R 25/70 Adaptation of deaf aid to hearing loss, e.g. initial electronic fitting
• CPC Class Codes: H04R 5/04 Circuit arrangements, e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments combinations of amplifiers H03F3/68; stereophonic systems H04S

Abstract

Making use of a digital acoustic signal processing apparatus arranged by employing memory device for storing a digital acoustic signal, acoustic frequency feature enhancing device for enhancing an acoustic frequency feature, and low-speed sound reproducing device for changing a speed of the stored voice to reproduce this voice as a low speed into a hearing aid and an appliance with an acoustic output, a hearing function difficulty due to an age is aided in utilization of audio output appliances such as a hearing aid, television receiver, and a telephone receiver. After the voice has been stored in the memory device, a process for enhancing the frequency characteristic in order to fit the frequency characteristic to the individual hearing characteristic and the voice reproducing environment is carried out and thereafter represented to the user. The user can repeatedly listen the voice stored in the memory device with employment of control device for controlling the voice reproducing operation. Furthermore, since a process for expanding a time scale during a sound reproducing operation is carried out, the voice can be represented at the low speed. Since the voice whose frequency characteristic has been enhanced can be represented at the low speed in order that either an individual hearing ability, or an apparatus is fitted to a using environment, hearing articulation can be improved with respect to such a hearing, the frequency resolution and the time resolution are simultaneously deteriorated.

Claims

1. A digital voice processing apparatus, comprising:

process means which carries out a frequency processing for changing a frequency characteristic without changing a time scale thereof and a temporal length processing to expand the time scale of a voice without changing a pitch interval thereof with the voice digitized; and

a control means which indicates a commencement and end for one of the frequency processing and the temporal length processing to be carried out by the process means, wherein

the process means which carries out the temporal length processing such that a time-region harmonic structured expansion and contraction processing is applied to a voice portion having a periodical waveform and that a silent period of the voice is expanded.

2. A digital voice processing apparatus according to claim 1, wherein a parameter used for one of the frequency processing and the temporal length processing is adjusted in accordance with an aural characteristic of user.

3. A digital voice processing apparatus as claimed in claim 1, wherein said temporal length processing of temporal length includes interposing a silent period between voiced parts of an acoustic signal.

4. A digital voice processing apparatus as claimed in claim 1, wherein said digital voice processing apparatus is for processing an analog input acoustic signal corresponding to a received acoustic signal of a bi-directional communication signal having both a received acoustic signal and a transmit acoustic signal, said digital voice processing apparatus further comprising:

a telephone receiver including both a speaker for outputting an analog acoustic signal converted by a D/A converter and a microphone for picking up a narrator'"'"'s voice;

a mixer for mixing an output of said microphone with a control signal when no narrator'"'"'s voice is being inputted from said microphone, said control signal indicating that a listener is still hearing a time-expanded presentation of said narrator'"'"'s voice by said digital voice processing apparatus; and

a receiver circuit including a transmitter circuit which is coupled to said digital voice processing apparatus, wherein said receiver circuit receives said analog input acoustic signal from said bi-directional communication signal to convert a band of said analog input into an audible band.

5. A digital voice processing apparatus as claimed in claim 1, wherein said control means is adapted to indicate a stored digital acoustic signal relating to an inputted voice signal of a predetermined time interval prior to the indication of the user.

6. A digital voice processing apparatus, including:

an A/D converter for digitizing a voice signal to be inputted;

a memory for storing the digital voice signal output from the A/D converter;

a processor for processing the digitized voice signal output from the A/D converter for converting the processed digital voice signal into an analog signal, wherein

the processor processes the digital voice signal with use of a programming for processing the voice frequency characteristic and another programming for expanding a time scale of the voice signal, in response to an instruction from a controller, and

the programming for expanding the time scale of the voice signal executes one of a time-region harmonic structured expansion and contraction processing for a voice portion having a periodical waveform and an expansion processing for a silent period of the voice signal, expanding the time scale of the voice signal.

7. A digital voice processing apparatus as claimed in claim 6, wherein said controller indicates a stored digital acoustic signal relating to an inputted voice signal of a predetermined time interval prior to selection of a reproduction mode by the user.

8. A digital voice processing method, comprising the steps of:

(a) indicating a digital voice signal stored in a memory in response to selecting one of a first mode and a second mode by user; and

(b) processing a frequency characteristic and a time scale for the indicated digital voice signal, wherein

in the step (a), the digital voice signal stored in the memory is indicated in time series at the first mode, the digital voice signal stored therein is indicated by going back in time in the second mode, and wherein

in the step (b), the time scale processing is carried out by one of each of such that a time-region harmonic structured expansion and contraction processing is applied to a voice portion having a periodical waveform and that a silent period of the voice is expanded.