Released on: April 4, 2008, 5:04 am

Press Release Author: Nataly Protopopova/ GritTec Ltd.

Industry: Telecommunications

Press Release Summary: In the updated version of dual microphone array (DMA) module
Multiple Canceller (MC) updating has been made. Also integration DMA with technology
on the basis of Noise Cancellation (NC) has been made.

Press Release Body: In the updated version of dual microphone array (DMA) module
Multiple Canceller (MC) updating has been made. Also integration DMA with technology
on the basis of Noise Cancellation (NC) has been made (fig.1.).
GritTec\'s Combo-SpeechEnhancer is complex using of technologies DMA and NC allows at
first by means of DMA to suppress all external hindrances and background noises in a
direction of the chosen speech source, and then by means of NC to suppress all
remained external noises and absent-minded hindrances what DMA could not suppress
completely. The sources of external hindrances can be an external noise of car,
speech of collocutor, music and any other sounds, coming from directions, different
from direction of the chosen source of the speech.
The made updating in MC allowed to receive on an output of the dual microphone array
the clear speech with lower speech distortions and higher suppression of external
hindrances and noises. This result was possible to reach at the expense of work
optimization of the adaptive filters which used in module MC.
Also this updating in MC automatically allows expanding quantity of adaptive filters
for suppression of other external hindrances and suppression of an acoustic echo. At
the moment experiments on suppression of other external hindrances and an acoustic
echo are not finished yet.
General features of GritTec’s Combo-SpeechEnhancer (ver.1,0):
- Support of 1 or 2 microphones configurations;
- Configurations: DMA&NC, DMA or NC;
- Delay of the algorithm: 8 ms;
- Noise suppression not less 25 db (for DMA&NC);
- High quality of speech enhancement.
General features for new version DMA (ver.1,3):
- Support of 2 microphones configurations;
- Delay of the algorithm: 8 ms;
- Directional microphones: unidirectional configuration (omni-uni directional);
- Distance between microphones not less 0.04 meters;
- Distance to the speaker not less 0.5 meters (up to 5 meters (?));
- Choice of a direction of a speech source: hand control;
- Noise suppression not less 15 db;
- Low level of speech distortion.

Examples of work GritTec\'s Combo-SpeechEnhancer you can found on a company website.
At the moment demonstration version of GritTec’s Combo-SpeechEnhancer is
accessible only on request. Some parameters at the moment are still specified.

About GritTec
GritTec Laboratory (GritTec Ltd.) specializes on research and development of
algorithms and technologies in the field of speech and audio processing. GritTec\'s
research is focused on speech enhancement, speech concealment, voice biometric,
speech recognition, speech synthesis and other speech and audio technologies.
url: http://www.grittec.com

Web Site: http://www.grittec.com

Contact Details: GritTec Ltd.
91, Bld.2, Svobody str.,
Moscow, 125481, Russia Federation.