SYSTEM AND METHOD FOR ADJUSTING AN AUDIO SIGNAL

• US 20090276067A1
• Filed: 07/10/2009
• Published: 11/05/2009
• Est. Priority Date: 05/28/2004
• Status: Active Grant

• Current Assignee: Blackberry Limited
• Original Assignee: Blackberry Limited
• Inventors: FORRESTER, Christopher, Nguyen, Bao, Hawker, Larry
• Granted Patent: US 8,300,848 B2
• Time in Patent Office: Days
• US Class Current: 700/94
• CPC Class Codes: G10K 11/175 using interference effects; Masking sound
• CPC Class Codes: H03G 5/165 Equalizers; Volume or gain control in limited frequency bands
• CPC Class Codes: H04M 1/03 Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets
• CPC Class Codes: H04M 1/23 Construction or mounting of dials or of equivalent devices; Means for facilitating the use thereof by improving visibility H04M1/22

Abstract

Disclosed is a system and method of adjusting a volume level for an audio signal for a communication device to comply with a quality threshold. The method comprises: obtaining a digitized signal value of the audio signal and monitoring for an increase in the volume level. In the method, upon determining that implementing the increase in the volume level would produce an output that would exceed the quality threshold, processing the signal value to produce a first output signal value for the audio signal utilizing a digital signal processing (DSP) device in the communication device, a processing filter defined in the digital signal processing device, a first set of adjustment parameters and the signal value. In the method, upon determining that implementing the increase in the volume level would not exceed the quality threshold processing the signal value to produce a second output signal value for the audio signal utilizing the DSP, the processing filter, a second set of adjustment parameters and the signal value. In the method, the first output signal and the second output signal both implement the increase in the volume level.

Claims

1. A method of adjusting a volume level for an audio signal for a communication device to comply with a quality threshold, said method comprising:

obtaining a digitized signal value of said audio signal;

monitoring for an increase in said volume level;

upon determining that implementing said increase in said volume level would produce an output that would exceed said quality threshold

processing said signal value to produce a first output signal value for said audio signal utilizing a digital signal processing (DSP) device in said communication device, a processing filter defined in said digital signal processing device, a first set of adjustment parameters and said signal value;

and

upon determining that implementing said increase in said volume level would not exceed said quality threshold

processing said signal value to produce a second output signal value for said audio signal utilizing said DSP, said processing filter, a second set of adjustment parameters and said signal value,

wherein said first output signal and said second output signal both implement said increase in said volume level.

2. The method of adjusting a volume level for an audio signal for a communication device, as claimed in claim 1, wherein said quality threshold is an audio frequency pass mask.

3. The method of adjusting a volume level for an audio signal for a communication device, as claimed in claim 2, wherein said audio frequency pass mask is a mask compliant with GSM standards.

4. The method of adjusting a volume level for an audio signal for a communication device, as claimed in claim 2, wherein:

said processing filter is a finite impulse response (FIR) filter;

said first set of adjustment parameters is a first set of coefficients for said FIR filter; and

said second set of adjustment parameters is a second set of coefficients for said FIR filter.

5. The method of adjusting a volume level for an audio signal for a communication device, as claimed in claim 4, wherein said second set of adjustment parameters provides a set of coefficients to adjust said audio signal to roll off lower frequency components in said audio signal.

6. The method of adjusting a volume level for an audio signal for a communication device, as claimed in claim 5, wherein said second set of adjustment parameters provides a set of coefficients to further adjust said audio signal to boost higher frequency components in said audio signal.

7. A system for adjusting a volume level for an audio signal for a communication device in compliance with a quality threshold, said system comprising:

a module to accept a request for change of volume for said audio signal;

a module to receive said audio signal and convert said audio signal to a digitized audio signal;

a microprocessor;

a digital signal processor for processing said digitized audio signal and producing a digital output signal utilizing a filter, said digitized audio signal and a set of parameters;

a first module providing a set of instructions operating on said microprocessor, said set of instructions;

determining when said request for change of volume occurs;

identifying a new volume level for said audio signal for said request;

upon determining that implementing said new volume level would produce an output that would exceed said quality threshold

producing a first output volume signal through said digital signal processor using a first set of adjustment parameters as said set of parameters and said new volume level;

and

upon determining that implementing said new volume level would produce an output that would not exceed said quality threshold

producing a second output volume signal through said digital signal processor using a second set of adjustment parameters as said set of parameters and said new volume level; and

and

a second module to convert said digitized audio signal to an analog audio signal and to provide said analog audio signal to a speaker,

wherein said first output signal and said second output volume signal both implement said change in said volume level.

8. The system for adjusting an audio signal for a communication device as claimed in claim 7, wherein said quality threshold is an audio frequency pass mask.

9. The system for adjusting an audio signal for a communication device, as claimed in claim 8, wherein said audio frequency pass mask is a mask compliant with GSM standards.

10. The system for adjusting an audio signal for a communication device as claimed in claim 7, wherein:

said filter is a finite impulse response (FIR) filter;

said first set of adjustment parameters is a first set of coefficients for said FIR filter; and

said second set of adjustment parameters is a second set of coefficients for said FIR filter.

11. The system for adjusting an audio signal for a communication device, as claimed in claim 7, wherein said second set of adjustment parameters provides a set of coefficients to adjust said audio signal to roll off lower frequency components in said audio signal.

12. The system for adjusting an audio signal for a communication device, as claimed in claim 11, wherein said second set of adjustment parameters provides a set of coefficients to further adjust said audio signal to boost higher frequency components in said audio signal.

13. A circuit for adjusting an output audio signal of a communication device in compliance with a quality threshold, said circuit comprising:

a module for receiving a signal encoding an audio signal and converting said signal to a digitized signal;

a module to accept a request for an increase in a current volume setting to an increased volume level for said output audio signal;

a microprocessor provided with instructions to detect when said request for said increase occurs and to generate an adjusted version of digitized signal to implement said increased volume level utilizing a digital signal processor (DSP);

a filter; and

said digitized signal; and

a module to convert said adjusted version of the digitized signal to an analog audio signal and to provide said analog audio signal to a speaker,

wherein the circuit

determines if said request for said increase at said increased volume level would generate an audio output signal which exceeds said quality threshold;

upon determining that said increased volume is within said quality threshold, selects a first set of adjustment parameters to be used by said digital signal processor to generate an adjusted version of said digitized signal to implement said increased volume having a received loudness rating (RLR) level; and

upon determining that said increased volume would cause said output audio signal to exceed said quality threshold, selects a second set of adjustment parameters to be used by said digital signal processor to generate another adjusted version of said digitized signal that provides different output levels for said digitized signal at different frequencies as compared to said adjusted version to have an acceptable characteristic for said quality threshold while implementing said increased volume at about said RLR level.

14. The circuit as claimed in claim 13, wherein said quality threshold is an audio frequency pass mask.

15. The circuit as claimed in claim 14, wherein:

said acceptable characteristic is a frequency response within an acceptable boundary of said audio frequency pass mask;

said filter is a finite impulse response (FIR) filter;

said first set of adjustment parameters is a first set of coefficients for said FIR filter; and

said second set of adjustment parameters is a second set of coefficients for said FIR filter.

16. The circuit as claimed in claim 15, wherein said audio frequency pass mask is compliant with GSM standards.

17. The circuit as claimed in claim 16, wherein said second set of adjustment parameters comprises a set of coefficients to roll off lower frequency components in said audio signal.

18. The circuit as claimed in claim 17, wherein said second set of adjustment parameters further comprises a set of coefficients to boost higher frequency components in said audio signal.

19. The circuit as claimed in claim 14, wherein:

said audio frequency pass mask defines a boundary associated with one of the following attributes relating to said audio signal;

a signal boost for selected signals;

gain adjustment;

side tone frequency adjustment;

switching adjustments;

signal suppression; and

adjustments for a microphone in said communication device;

said filter is a finite impulse response (FIR) filter;

said first set of adjustment parameters is a first set of coefficients for said FIR filter; and

said second set of adjustment parameters is a second set of coefficients for said FIR filter.