DSP audio chips from Dialog optimised for voice control

The two new DSP and CODEC integrated audio processor chips DA7322 and DA7323 from Dialog Semiconductor are designed for applications with voice/speech control in smart phone and tablets where multiple number of microphones are used.

Voice control is increasingly used in the recent smart phones, tablets computers, automotive infotainment systems and also in smart watches and other wearable devices. The accuracy of voice control is highly dependent on front-end voice processing, where multiple microphones and 24 bit codecs integrated with DSP are used. Higher signal-to-noise ratio is important factor.

DA7322 and DA7323 is packed with complete voice engine with 35dB signal-to-noise ratio (SNR). These devices support using up to four microphones for multi-channel beamforming, noise suppression and acoustic echo cancellation. DA7322 and DA7323 voice engines not only provide reliable voice control but also quality speech for telephonic conversation.

“There is an increasing need to improve the audio quality of voice calls,” said Udo Kratz, Senior Vice President and General Manager, Business Group Mobile Systems at Dialog. “Independent of the ambient noise conditions the consumer is experiencing, both audio CODECs deliver a superior audio experience by significantly reducing unwanted noise while maintaining voice quality during VOIP calls on applications such as Skype or Lync.”

Dialog semiconductor is targeting wearables by making available a low power voice trigger on the DA7322 and DA7323 where over a dozen keywords can be supported with over 95% accuracy. This feature is demonstrated by voice control software TrulyHandsfree from sensory.
Some of the speech/voice controls include trigger to search, user-defined triggers, speaker verification and identification and multiple language support.

These voice processor chips offer flexibility in terms of microphone placement to support beamforming so that they support both endfire and multi-MIC configurations. Beamforming algorithm can suppress stationary and non-stationary noise sources selectively.

The audio enhancements supported in the digital signal processor includes multiband equalisation, stereo widening, and psychoacoustic bass boost. In case the phone is using low-cost speaker the DSP engine can boast the bass part of the audio so that the listener is not disappointed in the effect of the music.

These chips can detect 3- or 4-pole jack and the type of headset without the need for any external adapters. The DA7322 can support four analogue microphones. The DA7323, by contrast, offers support for three analogue or two pairs of stereo digital microphones.

The Dialog DA7322 and DA7323 each come in a 66 bump WL-CSP package. These devices are currently available.