Toshiba Electronics Europe (TEE) has unveiled the TC94B24WBG audio codec, a highly integrated single microphone noise cancellation (NC) and echo cancellation (EC) solution for high-quality voice on smartphones and portable devices. The TC94B24WBG has been designed to offer 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 will allow customers to implement their own software in the audio codec, helping them to differentiate their products.
The highly integrated TC94B24WBG includes: a 2-channel AECM interface; a 4-channel DECM interface; a battery-conserving class-G headphone amplifier; ear speaker amplifier; asynchronous sampling rate converter; a 4-channel I2S interface; an 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. It comes equipped with two analogue and four digital microphone inputs to suit various customers’ needs. However, Toshiba’s audio processing algorithm needs just one analogue microphone to efficiently provide NC and EC simultaneously.
Noise cancellation on the TC94B24WBG is achieved through a Toshiba proprietary one microphone algorithm. The algorithm distinguishes voice and noise with statistical noise estimation while Toshiba’s improved minimum mean square error method in frequency-domain removes noise only and keeps the voice natural. The echo cancellation algorithm has a time-domain echo cancelling adaptive filter and frequency-domain echo suppression. The former removes linear echo, the later suppresses the rest of non-linear echo. These two main processes work together intelligently to achieve high quality echo cancellation by the same microphone used for the noise cancellation.
The audio codec is currently sampling with mass production scheduled to begin in February 2013. The device will be demonstrated at the 2013 Consumer Electronics Show in Las Vegas, Nevada.