Method and system for selectively and variably attenuating audio data

• US 6,498,855 B1
• Filed: 04/17/1998
• Issued: 12/24/2002
• Est. Priority Date: 04/17/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kokkosoulis, George, Temple, Daniel Anthony
• Primary Examiner(s): Isen, Forester W.
• Assistant Examiner(s): MCCHESNEY, ELIZABETH A
• Application Number:
  US09/061,985
• Time in Patent Office: 1,712 Days
• Field of Search: 381/104, 381/106, 381/107, 381/109, 700/94, 330/14
• US Class Current: 381/106
• CPC Class Codes: H03G 7/007 of digital or coded signals

Abstract

A method and system for selectively and variably attenuating audio data are disclosed. A high-volume control value as selected by a user is first received, and this high-volume control value defines a volume output level for high amplitude audio samples. An attenuation factor is then determined by utilizing the high-volume control value. Each sample from an incoming audio data stream is conditionally attenuated with the attenuation factor such that high amplitude audio data get compressed while low amplitude audio data remain unaffected. Finally, the attenuated samples are sent to an output.

Claims

1. A method for selectively and variably attenuating audio data, said method comprising the steps of:

receiving a high-volume output control value as selected by a user, wherein said high-volume output control value defines a volume output level for high amplitude audio samples;

determining an attenuation factor utilizing said high-volume output control value by calculating $y_{\max }={10}^{\frac{D-A}{20}}$$n=\frac{x_{\max }}{x_{\max }-y_{\max }}$$L=\frac{x_{\max }-y_{\max }}{x_{\max }^n}$

 

wherein A is said high-volume output control value in decibels, D is the maximum decibel range, x_max represents the maximum absolute input sample amplitude, y_max represents the maximum absolute output decimal sample amplitude, L is a coefficient, and n is said attenuation factor;

attenuating each sample from an incoming audio data stream with said attenuation factor; and

outputting said attenuated samples.

2. The method according to claim 1, wherein said attenuating step further includes calculating

3. The method according to claim 2, wherein said M equals one.

4. An audio system capable of selectively and variably attenuating audio data, comprising:

means for receiving a high-volume output control value as selected by a user, wherein said high-volume output control value defines a volume output level for high amplitude audio samples;

means for determining an attenuation factor utilizing said high-volume output control value by calculating $y_{\max }={10}^{\frac{D-A}{20}}$$n=\frac{x_{\max }}{x_{\max }-y_{\max }}$$L=\frac{x_{\max }-y_{\max }}{x_{\max }^n}$

 

wherein A is said high-volume output control value in decibels, D is the maximum decibel range, x_max represents the maximum absolute input sample amplitude, y_max represents the maximum absolute output decimal sample amplitude, L is a coefficient, and n is said attenuation factor;

means for attenuating each sample from an incoming audio data stream with said attenuation factor; and

means for outputting said attenuated samples.

5. The audio system according to claim 4, wherein said attenuating means further includes a means for calculating

6. The audio system according to claim 5, wherein said M equals one.

7. A computer program product residing on a computer usable medium for selectively and variably attenuating audio data, said computer program product comprising:

program code means for receiving a high-volume output control value as selected by a user, wherein said high-volume output control value defines a volume output level for high amplitude audio samples;

program code means for determining an attenuation factor utilizing said high-volume output control value by calculating $y_{\max }={10}^{\frac{D-A}{20}}$$n=\frac{x_{\max }}{x_{\max }-y_{\max }}$$L=\frac{x_{\max }-y_{\max }}{x_{\max }^n}$

 

wherein A is said high-volume output control value in decibels, D is the maximum decibel range, x_max represents the maximum absolute input sample amplitude, y_max represents the maximum absolute output decimal sample amplitude, L is a coefficient, and n is said attenuation factor;

program code means for attenuating each sample from an incoming audio data stream with said attenuation factor; and

program code means for outputting said attenuated samples.

8. The computer program product according to claim 7, wherein said program code means for attenuating further includes a program code means for calculating

9. The computer program product according to claim 8, wherein said M equals one.