Apparatus and methods for including codes in audio signals
US7961881B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 2005 |
| Grant date | Jun 14, 2011 |
| Priority date | — |
| Expiry date | Nov 4, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H60/66
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Apparatus and methods for including a code having at least one code frequency component in an audio signal are provided. The abilities of various frequency components in the audio signal to mask the code frequency component to human hearing are evaluated and based on these evaluations an amplitude is assigned to the code frequency component. Methods and apparatus for detecting a code in an encoded audio signal are also provided. A code frequency component in the encoded audio signal is detected based on an expected code amplitude or on a noise amplitude within a range of audio frequencies including the frequency of the code component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.