Audyssey Builds on Sound Correction Technology for Headphone Market

Audyssey announced the ExpertFit partner program, based around a software development kit (SDK) for headphone manufacturers who want to differentiate products using Audyssey’s headphone calibration technology. ExpertFit is a measurement and listening tool based on algorithms derived from Audyssey’s MultEQ and Dynamic EQ technologies used in AV receivers, music systems, car audio, TVs and PCs, the company said Friday. Under the ExpertFit program, Audyssey creates a unique profile for each pair of headphones, it said. The profiles can be used within Audyssey’s own media player, called Amp, and also within the Songza music-streaming service, Audyssey said. The app-based approach brings advanced processing power to headphones for the first time, Audyssey said.

"If you try to equalize headphones to a flat response, you're not taking into account in-ear issues,” Audyssey Chief Technology Officer Chris Kyriakakis told Consumer Electronics Daily. MultEQ takes into account time domain issues associated with loudspeakers in a room and Dynamic EQ applies correction to restore balance to audio without having to turn volume up to levels in which sound was recorded, Kyriakakis said. Audyssey’s ExpertFit program enables the same kind of sound tweaking to be applied to headphones.

During the research phase, Audyssey engineers visited sound studios to determine differences between what is heard by audio engineers at the mixing console and what is heard through headphones by placing miniature microphones inside an ear canal simulator positioned in a mannequin made from aluminum, Kyriakakis said. “We found a way to translate the response of a good calibrated studio at the mixing position to inside the ear canal,” Kyriakakis said. During the processing, MultEQ sends a test signal, receives it back, measures the difference and applies a translation from speaker to ear canal, he said.

Ideally, Audyssey would like to offer a button that enables listeners to hear music as it was recorded in the studio, Kyriakakis said, but every headphone is different according to various factors including build materials, amount of distortion and frequency response. Through the years, consumers have been given control of sound through multi-band graphic equalizers with “terrible interfaces that they know nothing about,” Kyriakakis said. Typically a consumer turns up or down all the sliders or “makes them into silly shapes that have nothing to do with anything,” he said. Audyssey’s solution for consumer adjustment is a tilt control, a left-to-right slider that gives fine control of treble and bass without affecting the midrange, he said. Audyssey makes that control available to consumers on its 99-cent iPhone Amp app that it launched in February. Using that app, consumers can optimize their music to specific headphone brands and fine-tune adjustments from there.

In the ExpertFit program, Audyssey offers headphone makers the same kind of controls to customize their “signature sound” to what they'd like it to be, Kyriakakis said. Audyssey has 200 profiles in its cloud-based database for the top-selling headphones in the U.S., based on NPD data, and has calibrated algorithms for those headphones to studio reference frequency response, Kyriakakis said. As news of the company’s efforts spread, manufacturers began asking if they could get a customized version of the profiles, which prompted the ExpertFit program, he said. The SDK will also be available under license to streaming companies, he said.

Companies can participate in the Audyssey partner program on several levels. At the minimum, partners will use the Audyssey player with the company’s calibration method and profiles, in a cross-promotion arrangement. In the step-up program, Audyssey will customize the media player in a white-label model, offering a turnkey media player for a manufacturer that wants to restrict the headphone database to its own line. The latter gives those manufacturers an “instant way to enter the iOS ecosystem” with a media player and dedicated processing tailored to their headphones, he said. Audyssey’s app is only available for iOS devices today, but the SDK is available for iOS and Android platforms, he said.

Audyssey amassed a voluminous database of information during the process of testing headphone models, he said. “I'm pretty sure we have more data on every headphone than the manufacturer does,” he said, adding that a 20-page automated report is generated with each test Audyssey performs. The Audyssey headphone technology is designed to work with a full range of products from $10 headphones up to multi-hundred-dollar models, Kyriakakis said. But, he said, “The better the starting point, the better the final result.”