Feature-based level control

Patent metadata

Field	Value
Publication number	US-9331649-B2
Application number	US-201313743487-A
Country	US
Kind code	B2
Filing date	Jan 17, 2013
Priority date	Jan 27, 2012
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

A computer-implemented method comprising: determining one or more features of a subject signal; revising one or more control signals on the basis of the one or more features; modifying a level of the subject signals based on the control signals. At least one of the features is determined by: comparing a given one of the subject signals against a boundary signal to produce a corresponding given boundary comparison signal; and summarizing the behavior of the given boundary comparison signal over a time interval.

First claim

What is claimed is:

1. A sound processing method executed at a sound processing device, comprising:
determining one or more features of an envelope generated from an input sound signal;
revising one or more control signals on the basis of the one or more features;
modifying a level of the envelope based on the control signals to generate a scaled envelope; and
generating an output signal based on the scaled envelope,
wherein at least one of the one or more features is determined by:
comparing the envelope against a boundary signal to produce a boundary comparison signal; and
summarizing the behavior of the boundary comparison signal over a time interval.

2. The method of claim 1 , wherein at least one of the one or more control signals is a gain that is applied to the envelope.

3. The method of claim 1 , wherein at least one of the one or more control signals is the saturation level of a loudness growth function that is applied to the envelope.

4. The method of claim 1 , wherein at least one of the one or more control signals is the base level of a loudness growth function that is applied to the envelope.

5. The method of claim 1 , wherein the summarizing step includes accumulating the boundary comparison signal over a time interval so as to produce a count.

6. The method of claim 5 , wherein the summarizing step further includes filtering the count.

7. The method of claim 1 , wherein the summarizing step includes filtering the boundary comparison signal.

8. The method of claim 1 , wherein the step of comparing the envelope against the boundary signal further comprises:
subtracting the boundary signal from the envelope so as to produce a difference signal; and
half-wave rectifying the difference signal.

9. The method of claim 1 , wherein the boundary signal is equal to a desired maximum level of the envelope.

10. The method of claim 1 , wherein at least one of the features is indicative of a proportion of instances that the envelope exceeds the boundary signal.

11. The method of claim 1 , further comprising:
performing a frequency analysis on an input sound signal to generate a plurality of analysis signals; and
performing envelope detection on the analysis signals to generate a plurality of envelopes, wherein the envelope is one of the plurality of envelopes.

12. The method of claim 11 , further comprising:
multiplying each of the plurality of envelopes by a corresponding one of a plurality of scaling values to produce a plurality of sizing signals,
wherein a scaling value applied to the envelope is one of the plurality of sizing values.

13. The method of claim 12 , wherein the scaling value applied to the envelope is a gain value.

14. The method of claim 1 , wherein the sound processing device is part of a hearing prosthesis including a microphone; and wherein the method further comprises:
obtaining the input signal at the microphone;
deriving the envelope from the input sound signal obtained from the microphone;
generating stimulation signals based on the scaled envelope according to the one or more control signals; and
stimulating tissue of a recipient of the hearing prosthesis according to the stimulation signals.

15. A sound processing method executed at a sound processing device, comprising:
performing a frequency analysis on an input sound signal to generate at least one analysis signal;
multiplying the analysis signal by a scaling value to produce a scaled analysis signal;
determining one or more features of a scaled envelope determined based on the scaled analysis signal; and
revising a scaling value for application to the analysis signal on the basis of a comparison between the one or more features and one or more decision thresholds;
wherein at least one of the features is determined by:
comparing the envelope to a boundary signal, to produce a boundary comparison signal; and
summarizing the behavior of the boundary comparison signal over a time interval.

16. The method of claim 15 , further comprising:
performing a frequency analysis on an input sound signal to generate a plurality of analysis signals; and
multiplying each of the plurality of analysis signals by a corresponding one of a plurality of scaling values to produce a plurality of scaled analysis signals;
performing envelope detection on the plurality of scaled analysis signals to generate a plurality of scaled envelopes.

17. The method of claim 15 , wherein the scaling value is a gain value.

Assignees

• Cochlear Ltd

Inventors

• Swanson Brett Anthony
• Khing Phyu Phyu

Classifications

• H04R25/356

  Amplitude, e.g. amplitude shift or compression · CPC title

• H04R25/505

  using digital signal processing · CPC title

• H03G1/00 Primary

  Details of arrangements for controlling amplification · CPC title

• H04R2430/03

  Synergistic effects of band splitting and sub-band processing · CPC title

• H04R25/70

  Adaptation of deaf aid to hearing loss, e.g. initial electronic fitting · CPC title