Method and device for providing a plurality of audio files with consistent loudness levels but different audio characteristics

• US 8,571,235 B2
• Filed: 04/16/2012
• Issued: 10/29/2013
• Est. Priority Date: 07/11/2008
• Status: Expired due to Fees

• Current Assignee: Nuance Communications, Inc. (Microsoft Corporation)
• Original Assignee: Nuance Communications, Inc. (Microsoft Corporation)
• Inventors: Naylor, Patrick
• Primary Examiner(s): Neway, Samuel G
• Application Number:
  US13/447,502
• Publication Number:
  US 20120209602A1
• Time in Patent Office: 561 Days
• Field of Search: 381104-109
• US Class Current: 381/107
• CPC Class Codes: H03G 9/005 of digital or coded signals
• CPC Class Codes: H03G 9/025 frequency-dependent volume compression or expansion, e.g. multiple-band systems H03G9/10, H03G9/18 take precedence

Abstract

The invention provides a method and device for enhancing the listening qualities of an audio file by providing the listener with a plurality of modified equalized audio files. Each modified equalized audio file having a consistent loudness level but different audio characteristics. Hence, for an input audio file the current invention allows the listener to individually select the best audio characteristics for them to listen to the content of the input audio file according to their particular requirements without them needing to adjust the loudness level in playback. The invention further enables the listener to switch between the multiple equalized audio files during playback. The invention further includes a SN detector and reducer to eliminate the adverse effects of the presence of sudden, strong noise in the input audio file in the process of generating the plurality of modified equalized audio files.

Claims

1. A method for processing an audio file to produce a plurality of modified equalized audio files with different audio characteristics but a consistent level of loudness comprising the steps of:

receiving an audio file;

generating a plurality of equalized audio files from said audio file;

modifying each equalized audio file to produce the plurality of modified equalized audio files by;

determining an activity level of the equalized audio file;

calculating a loudness multiple from a constant and the activity level; and

multiplying the equalized audio file by the loudness multiple; and

synchronizing the plurality of modified equalized audio files for playback permitting a user to switch between the plurality of modified equalized audio files during playback.

2. The method of claim 1, wherein the loudness multiple is calculated from the multiple of the constant and the activity level.

3. The method of claim 1, wherein the method further includes detecting a presence of a sudden, strong noise in the audio file.

4. The method of claim 3, wherein the method further includes reducing the presence of the sudden, strong noise in the audio file.

5. The method of claim 1, wherein the activity level is a speech activity level.

6. The method of claim 1, wherein a plurality of preset equalization profiles is used to create the plurality of equalized audio files.

7. The method of claim 6, wherein the preset equalization profiles are at least two of slim, shine, clarity, bright, and null.

8. A device for processing an audio file to produce a plurality of modified equalized audio files with different audio characteristics but a consistent level of loudness comprising:

a circuit for receiving an audio file and generating a plurality of equalized audio files, each of the plurality of equalized audio files being modified by the circuit to produce the plurality of modified equalized audio files for storing and playing to a user, the circuit modifying each of the plurality of equalized audio files by measuring an activity level of the equalized audio file against a constant to produce a loudness multiple, and the circuit multiplying the equalized audio file by the loudness multiple, wherein the circuit further synchronizes the plurality of modified equalized audio files for playback permitting the user to switch between the plurality of modified equalized audio files during playback.

9. The device of claim 8, wherein the circuit further comprises a Gain Factor, a Speech Activity Level Calculator, a plurality of Amplifiers, and a User Selectable Switch.

10. The device of claim 9, wherein the circuit further comprises a non-linear compressor in at least one of the Amplifiers.

11. The device of claim 8, wherein the device further includes a circuit for detecting a presence of a sudden, strong noise in the audio file.

12. The device of claim 8, wherein the device further includes a circuit for reducing the presence of the sudden, strong noise in the audio file.

13. A device for processing an audio file to produce a plurality of modified equalized audio files with different audio characteristics but a consistent level of loudness comprising:

a programmed general-purpose computer for receiving an audio file and generating a plurality of equalized audio files, each of the plurality of equalized audio files being modified by the programmed general-purpose computer to produce the plurality of modified equalized audio files for storing and playing to a user by the programmed general-purpose computer, the programmed general-purpose computer modifying each of the plurality of equalized audio files by measuring an activity level of the equalized audio file against a constant to produce a loudness multiple, and multiplying the equalized audio file by the loudness multiple, wherein the programmed general-purpose computer is further programmed to synchronize the plurality of modified equalized audio files for playback permitting the user to switch between the plurality of modified equalized audio files during playback.

14. The device of claim 13, wherein the audio file, equalized audio files, and modified equalized audio files are stored on a computer-readable storage medium.

15. The device of claim 13, wherein the programmed general-purpose computer is further programmed to detect a presence of a sudden, strong noise in the audio file.

16. The device of claim 13, wherein the programmed general-purpose computer is further programmed to reduce the presence of the sudden, strong noise in the audio file.