Toshiba audio codec integrates single microphone noise/echo cancellation technologies

USA: Toshiba America Electronic Components Inc. (TAEC) premiered its TC94B24WBG audio codec, a highly integrated single microphone noise cancellation (NC) and echo cancellation (EC) solution orchestrating high-quality voice on smartphones and portable devices.

The TC94B24WBG offers design flexibility, performance, and cost benefits so OEMs can better address challenges associated with multiple microphone audio processing.

Besides processing the NC/EC algorithms, the high-performance, low-power, general-purpose programmable DSP in the TC94B24WBG allows customers to implement their own software in the audio codec to help differentiate their products from the competition.

Additionally, the TC94B24WBG includes a 2-ch Analog Electret Condenser Microphone (AECM) interface, 4-ch Digital Electret Condenser Microphone (DECM) interface, a battery conserving class-G headphone amplifier, ear-speaker amplifier, asynchronous sampling rate converter, 4-ch I2S interface, I2C/SPI interface and audio post processing (equalizer, dynamic-range controller).

It provides all of the audio inputs and outputs required by mobile and telephony products. The device interfaces with the audio I/O and the application processor in smartphones and tablets. The TC94B24WBG comes equipped with two analog and four digital microphone inputs to suit a variety of customer needs. Toshiba's unique audio processing algorithm, however, needs just one analog microphone to efficiently provide NC/EC simultaneously.

"Toshiba once again delivers an innovative device that gives OEMs distinct advantages relative to price, performance and quality as they roll out next-generation mobile devices. Many companies have attempted single microphone Noise Cancellation/Echo Cancellation designs, but compromised on the performance. Toshiba believes its one microphone solution for audio processing delivers true voice sound while mindful of performance, area and design concerns associated with smaller smartphones and tablets," said Andrew Burt, VP of the Analog and Imaging Business Unit, System LSI Group at TAEC. "The end result is that consumers will appreciate the voice quality enabled by the new Toshiba audio codec on their hand-held devices."

Outstanding noise cancellation on the TC94B24WBG is achieved through a Toshiba proprietary one-microphone algorithm. The algorithm distinguishes between voice and noise with statistical noise estimation while Toshiba's improved minimum mean square error method in frequency domain removes noise only and makes the voice remain natural. The excellent echo cancellation algorithm has a time-domain echo cancelling adaptive filter and a frequency-domain echo suppression.

The former removes linear echo, the latter suppresses the residual non-linear echo. These two main processes work together closely and intelligently to achieve high-quality echo cancellation by the same microphone used for the noise cancellation.

The Toshiba TC94B24WBG is priced at $3 in 1K quantity. The audio codec is currently sampling with mass production scheduled to begin in February 2013.