Bluetooth headsets to get dual mics
Aussie developers use secondary mics for noise suppression
Adding a second microphone to a Bluetooth headset significantly improves its ability to capture speech by making it more effective at noise cancellation and suppression, according to Australian audio software developer Dynamic Hearing.
The company has added a multi-mic feature called VoiceField to its Atlas audio processing software for CSR's Bluetooth silicon. VoiceField uses two microphones, one in the usual place to capture the user's speech, and the other located elsewhere to pick up the background noise.
The software in effect subtracts the latter from the former, leaving what Dynamic Hearing's CEO, Dr Elaine Saunders, called "an extremely clean transmit signal".
This multi-mic idea is not new, but it requires memory and a fair chunk of compute power to process the audio streams. Dynamic Hearing said it chose CSR because CSR's BlueCore5-Multimedia chip has both memory and a DSP (digital signal processor) built-in.
Saunders added that VoiceField is the latest addition to Atlas, whose software features already include acoustic echo suppression, automatic handsfree volume control, and programmable equalisation in 33 frequency bands of both the transmitted and received audio signal.
CSR software marketeer Gemma Paris said that several CSR customers are developing multi-mic headsets for release later this year. She said that the Atlas software would be rolled up with software from CSR itself and flashed onto the headsets during production. ®
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