| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 379406120 | Frequency domain analysis | 6 |
| 20080304654 | METHOD AND SYSTEM FOR CLEAR SIGNAL CAPTURE - A method and system for clear signal capture comprehend several individual aspects that address specific problems in improved ways. In addition, the method and system also comprehend a hands-free implementation that is a practical solution to a very complex problem. Individual aspects comprehended related to echo and noise reduction, and divergence control. | 12-11-2008 |
| 20090103712 | CONTROLLING ECHO IN A WIDEBAND VOICE CONFERENCE - In one embodiment, an echo canceller configured to cancel echo in a wideband voice conference is provided. A double-talk condition may be when a plurality of users are speaking substantially simultaneously. When a double-talk condition is detected in the wideband conference, a high-frequency process is enabled and used to process signals in the high band to reduce echo. Accordingly, echo in the high band may not be produced by end devices being used by the users' speaking. Also, the users speaking have the echo cancelled in the low band and substantial echo does not result. This results in the users speaking experiencing the conference in the narrowband. The other users that are not speaking, however, continue to receive wideband signals. The users not speaking also continue to have echo cancellation performed for the high band and low band because these users are not speaking and thus attenuation of their voices is not a consideration. | 04-23-2009 |
| 20130044873 | Clock Skew Compensation for Acoustic Echo Cancellers Using Inaudible Tones - Methods and apparatus are provided for acoustic echo cancellation in a speech signal. Acoustic echo is cancelled by inserting at least one tone in the speech signal, wherein the at least one tone is substantially inaudible to a listener; determining a clock skew between two sampling clocks based on a frequency shift of the at least one tone; re-sampling the speech signal based on the determined clock skew; and performing the acoustic echo cancellation using the re-sampled speech signal. The provided acoustic echo cancellers can be implemented, for example, as terminal-based and/or network-based acoustic echo cancellers. The tone optionally comprises an inaudible tone or multiple tones. The tone generation can be limited to only when a speech power in the vicinity of the tone frequency is larger than a pre-determined threshold, or to the beginning of a call. A level of the tone can optionally be controlled so that the tone is masked by the speech signal. | 02-21-2013 |
| 20140219441 | VOICE ECHO CANCELLATION METHOD AND SYSTEM - A Voice Echo Cancellation system and process are disclosed. According to one embodiment, the present invention comprises an input audio source that is converted to a digital signal via a PCM convertor where the amplitude of the input audio source is sampled at regular intervals and translated into digital PCM audio. The resulting PCM audio is analyzed for its dynamic and harmonic content. Corrective sound waves are then generated that reduce the repetition of the original audio (echos). The corrective sound waves are applied to the repeating audio echoes to create corrected sound waves. The corrected audio is then outputted from the system. The analyzing step of the Voice Echo Cancellation process of the present invention comprises performing an evaluation of the PCM audio for dynamic and harmonic content; identifying repetitive harmonic content (echos) of the PCM audio; determining a scale based on the ratio of the amplitude of the first repeat harmonic to the amplitude of the input PCM audio; generating sound waves with descending amplitude levels according to the determined scale; and phase shifting the newly generated sound waves to generate corrective sound waves. The phase shift of the inventive Voice Echo Cancellation process is 90 to 180 degrees. | 08-07-2014 |
| 20150124959 | METHOD, SYSTEM AND DEVICE FOR REDUCING INTERFERENCE BETWEEN A FIRST AND A SECOND DIGITAL SUBSCRIBER LINE - The invention relates to a method and to a device for reducing interference between a first and a second digital subscriber line, DSL. A corresponding communication system is also provided. The invention provides a method wherein interference between a first and a second digital subscriber line is reduced, the method comprising the steps of determining line characteristics of the second DSL and reducing a transmission power of the first DSL based on the line characteristics of the second DSL. | 05-07-2015 |
| 20160094718 | Detection of Acoustic Echo Cancellation - An echo cancellation detector for controlling an acoustic echo canceller that is configured to cancel an echo of a far-end signal in a near-end signal in a telephony system, the echo cancellation detector comprising a comparison generator configured to compare the far-end signal with the near-end signal, a decision unit configured to make a determination about a first acoustic echo canceller based on that comparison and a controller configured to control an operation of a second acoustic echo canceller in dependence on the determination. | 03-31-2016 |
