Microphone circuitry enables sound detection and keyword recognition

The small System-in-Package (SiP) device integrates a low-power ST MEMS microphone enabled by DSP Group's ultra-low power voice-processing chip and Sensory's voice-recognition firmware. The solution leverages ST's advanced packaging technology to achieve a powerful yet lightweight package, extremely long battery runtimes, and advanced functionality.

Although typical wake-on-sound microphones eliminate the need for users to touch the device to wake it from sleep mode, they suffer from limited processing power and wake the main system processor to recognise the received instruction. Using the powerful computation capabilities from DSP Group, ST's microphone detects and recognises instructions without waking the main system, enabling energy-efficient, intuitive, and seamless interactions for users speaking to voice-operated appliances like smart speakers, TV remotes, and smart home systems.

The microphone solution taps DSP Group's HDClear ultra-low power audio processing chip to significantly reduce energy consumption, extending the lifetime of battery-operated equipment for several years without the need to recharge or replace battery. Responses to voice commands are also faster, because the system acts on the instruction immediately without first having to recognise it.

"Unlike previous existing solutions, this microphone doesn't just listen to voices - it immediately understands the commands, too, without using the power and computation resources of the main processor," commented Andrea Onetti, MEMS and Sensors Division General Manager, STMicroelectronics. "This smart integration step is a key enabler for the voice interfaces that are being added to IoT objects and applications, including those contributing to Industry 4.0."

"As voice becomes the default user interface, more and more innovative products embrace smart voice-processing technology. Our solution combines a small footprint, high integration, and the low-power consumption needed to enable seamless and effective voice user interfaces in battery-operated devices," said Ofer Elyakim, CEO of DSP Group. "Collaboration with industry leaders ST and Sensory on this smart microphone brings to market a powerful yet energy-efficient solution with best-in-class performance, which makes it a perfect match for any smart system that needs to incorporate high-quality voice capabilities."

Todd Mozer, CEO of Sensory, added: "Voice activation has the potential to transform the way people interact with all kinds of electronic equipment in the home, while on the go, or at work. ST's new highly integrated solution, leveraging our latest-generation firmware, is an important enabler for OEMs seeking to deliver a natural and fluid user experience."

First prototypes of ST's command-recognition microphone will be available by the end of Q1 2017 with volume production in early 2018.