Suppressing background sound could be critical during, for example, calls to your spouse or boss to explain why you're late. A noisy bar could sound a lot like a quiet office. But once you've spent the extra money for a phone with two microphones and an extra chip, you also get a benefit yourself: The Audience chip can analyze the background sounds coming from around the person you're talking to and cut out that noise as well, Watts said.
All this could mean a big leg up for phone makers that latch on to this technology, according to Avi Greengart, who analyzes the mobile industry at Current Analysis. At the moment, vendors are all pushing their browsers and music players, he said.
"The one thing that hasn't been claimed yet is the mantle of, 'Our phones make better phone calls,' " Greengart said.
Audience's Watts said the chip could go into Bluetooth headsets, where some effort has already been made at cleaning up noises, such as in the sleek Jawbone from Aliph. But he pointed out that the mobile phone market, about ten times the size of the headset industry, was more attractive.
The Audience Voice Processor is only 2.7mm by 3.5mm in size and sits between the microphones and the main baseband processor of a phone. It stands out from other audio chips in that it has to have both an analog-to-digital conversion piece (for bringing sounds from the microphones into the Audience chip) and a digital-to-analog converter to push the cleaned-up sounds to the main processor. Cellular baseband chips are used to getting sound directly from a handset's microphone as an analog signal.
Because it simply sends out an analog signal, the chip can be used with GSM (Global System for Mobile Communications), CDMA (Code-Division Multiple Access) or any other cellular technology, Watts said. It's currently available in the Sharp SH705ill handset in Japan and the LG Electronics LG-SH400 in South Korea.
In honor of the Audience chip's ability to conceal where secretive subscribers are calling from, SK Telecom is advertising the LG model as the "alibi phone."