Psychoacoustics for improved audio reproduction, power reduction, and speaker protection

Patent metadata

Field	Value
Publication number	US-2019230438-A1
Application number	US-201916255537-A
Country	US
Kind code	A1
Filing date	Jan 23, 2019
Priority date	Jan 25, 2018
Publication date	Jul 25, 2019
Grant date	—

Abstract

A method for processing audio data for output to a transducer may include receiving an audio signal, filtering the audio signal with a fixed filter having fixed filter coefficients to generate a filtered audio signal, and outputting the filtered audio signal to the transducer. The fixed filter coefficients of the fixed filter may be tuned by using a psychoacoustic model of the transducer to determine audibility masking thresholds for a plurality of frequency sub-bands, allocating compensation coefficients to the plurality of frequency sub-bands, and fitting the fixed filter coefficients with the compensation coefficients allocated to the plurality of sub-bands.

First claim

What is claimed is:

1 . A method for processing audio data for output to a transducer, comprising:
receiving an audio signal; filtering the audio signal with a fixed filter having fixed filter coefficients to generate a filtered audio signal; and outputting the filtered audio signal to the transducer; wherein the fixed filter coefficients of the fixed filter are tuned by:
using a psychoacoustic model of the transducer to determine audibility masking thresholds for a plurality of frequency sub-bands;
allocating compensation coefficients to the plurality of frequency sub-bands; and
fitting the fixed filter coefficients with the compensation coefficients allocated to the plurality of sub-bands.

2 . The method of claim 1 , wherein the fixed filter coefficients of the fixed filter are further tuned by repeating the using, allocating, and fitting steps to achieve a desired response of the filtered audio signal.

3 . The method of claim 2 , wherein the desired response is one or more of a desired audio enhancement of the audio signal, a desired power reduction, a desired speaker protection, and a desired impulse response of the filtered audio signal.

4 . The method of claim 1 , wherein the fixed filter coefficients of the fixed filter are further tuned by using a plurality of tuning signals to tune the psychoacoustic model.

5 . The method of claim 4 , wherein tuning of the filter coefficients of the fixed filter occurs offline.

6 . The method of claim 1 , further comprising calculating the compensation coefficients by using one of signal processing, statistical analysis, machine learning, and probabilistic analysis.

7 . The method of claim 1 , wherein the fixed filter is combined into a single filter that applies a combination of a response of the fixed filter and a response of a sonic audio enhancement filter.

8 . A method for processing audio data for output to a transducer, comprising:
receiving an audio signal; applying a plurality of filter banks to the audio signal, each of the plurality of filter banks corresponding to a plurality of frequency sub-bands, to determine a power of the audio signal within each of the plurality of frequency sub-bands; selecting which of the plurality of frequency sub-bands to apply compensation filtering based on, for each sub-band, a comparison of the power of the audio signal within such sub-band against a threshold associated with such sub-band; filtering the audio signal with a compensation filter configured to apply compensation filtering in the frequency sub-bands selected for compensation; and outputting the filtered audio signal to the transducer.

9 . The method of claim 8 , wherein the plurality of frequency sub-bands are psychoacoustic sub-bands associated with audibility of sound in such frequency sub-bands when generated by the transducer.

10 . The method of claim 8 , wherein selecting further comprises selection of one of the frequency sub-bands only to be used for compensating the audio signal.

11 . A system for processing audio data for output to a transducer, comprising:
a fixed filter configured to:
receive an audio signal;
filter the audio signal with a fixed filter having fixed filter coefficients to generate a filtered audio signal; and
output the filtered audio signal to the transducer; and
a psychoacoustic model of the transducer configured to tune the fixed filter coefficients of the fixed filter by:
determining audibility masking thresholds for a plurality of frequency sub-bands;
allocating compensation coefficients to the plurality of frequency sub-bands; and
fitting the fixed filter coefficients with the compensation coefficients allocated to the plurality of frequency sub-bands.

12 . The system of claim 11 , wherein the psychoacoustic model is further configured to tune the fixed filter coefficients of the fixed filter by repeating the using, allocating, and fitting steps to achieve a desired response of the filtered audio signal.

13 . The system of claim 12 , wherein the desired response is one or more of a desired audio enhancement of the audio signal, a desired power reduction, a desired speaker protection, and a desired impulse response of the filtered audio signal.

14 . The system of claim 11 , wherein the psychoacoustic model is further configured to tune the fixed filter coefficients of the fixed filter by using a plurality of tuning signals to tune the psychoacoustic model.

15 . The system of claim 14 , wherein tuning of the fixed filter coefficients of the fixed filter occurs offline.

16 . The system of claim 11 , wherein the psychoacoustic model is further configured to calculate the compensation coefficients by using one of signal processing, statistical analysis, machine learning, and probabilistic analysis.

17 . The system of claim 11 , wherein the fixed filter is combined into a single filter that applies a combination of a response of the fixed filter and a response of a sonic audio enhancement filter.

18 . A system for processing audio data for output to a transducer, comprising:
an input for receiving an audio signal; a plurality of filter banks applied to the audio signal, each of the plurality of filter banks corresponding to a plurality of frequency sub-bands; one or more power calculation blocks configured to determine a power of the audio signal within each of the plurality of frequency sub-bands; decision logic configured to select which of the plurality of frequency sub-bands to apply compensation filtering based on, for each frequency sub-band, a comparison of the power of the audio signal within such frequency sub-band against a threshold associated with such frequency sub-band; and a compensation filter configured to apply compensation filtering in the frequency sub-bands selected for compensation output of the filtered audio signal to the transducer.

19 . The system of claim 18 , wherein the plurality of frequency sub-bands are psychoacoustic sub-bands associated with audibility of sound in such frequency sub-bands when generated by the transducer.

20 . The system of claim 18 , wherein the decision logic is configured to select one of the frequency sub-bands only to be used for compensating the audio signal.

Assignees

• Cirrus Logic Int Semiconductor Ltd

Inventors

• Hatab Ziad
• Su Jie
• Lau Kaichow

Classifications

• H03G5/165

  Equalizers; Volume or gain control in limited frequency bands · CPC title

• G10L25/18

  the extracted parameters being spectral information of each sub-band · CPC title

• H04R3/04 Primary

  for correcting frequency response · CPC title

• H04R2430/03

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

• G10L25/21

  the extracted parameters being power information · CPC title