An audio codec has been developed by Toshiba Electronics Europe that is said to offer a highly integrated single microphone noise cancellation (NC) and echo cancellation (EC) solution for high-quality voice on smartphones and portable devices.
The company’s TC94B24WBG targets multiple microphone audio processing.
Besides processing the NC/EC algorithms, the DSP in this device enables implementation of software in an audio codec. This device 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 (equaliser, dynamic range controller). It is said to provide 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.
Noise cancellation is achieved through the company’s one microphone algorithm. The algorithm distinguishes voice and noise with statistical noise estimation while the company’s improved minimum mean square error method in frequency-domain is said to remove noise only and keep 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 closely and intelligently to achieve high quality echo cancellation by the same microphone used for the noise cancellation.
Toshiba Electronics Europe
