Digital audio data transmission system based on the information content of an audio signal
US5809472A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 3, 1996 |
| Grant date | Sep 15, 1998 |
| Priority date | — |
| Expiry date | Apr 3, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H20/88
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The data rate of speech and non-speech audio is selectively reduced by respective compression techniques based upon the information content of the type of signal. A composite audio information signal formed of speech and non-speech audio is applied to both a voice encoder and a wide-band audio compression encoder. An audio-type detection circuit examines the speech spectrum as well as the entire frequency spectrum and dynamic range of the audio information and generates a selection signal indicating whether the signal is speech or non-speech audio. A composite encoded audio signal is produced by intermingling the outputs of the encoders in response to the selection signal. The composite encoded audio signal and an identification signal indicative of the audio signal type are transmitted to respective receivers at the reduced data rates for storage, and subsequent decoding and retrieval by a listener as an audible signal in response to the transmitted identification signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.