Once the wake word is detected, the microphone can be used to rouse other parts of the system. The microphone can process voice commands—such as “Answer call” or “Raise the volume” or “Replay last song”—before the headphones send them over Bluetooth to the user's smartphone. The 43 MHz processor inside has access to a small amount of memory to remember a short list of voice commands.
"Today, digital assistants are activated by physical means [with] a press of a button or a tap," Peter Cooney, principal analyst at SAR Insight & Consulting, said in a statement. He added that "there will be rapid increase in the use of always-on voice triggers from 2019 onwards as battery density improves and more energy-efficient solutions such as smart microphones are implemented."
Last year, shipments of wireless earbuds like Apple's AirPods came to more than 40 million units, with total sales of $6 billion, according to estimates by SAR Insight & Consulting. Sales are projected to surge to $10 billion in 2019, with Apple maintaining its early market lead. Wireless earbuds will account for over 60% of all wireless stereo headphones shipped by 2023, the market researcher said.
Apple introduced its second generation of AirPods in March with the ability to wake its voice assistant by saying "Hey, Siri" instead of tapping a button on the side of the headphones. Samsung released a limited set of voice commands in April that can be used to control Galaxy Buds with its Bixby voice assistant. Bose has also added voice-activated Alexa to its latest line of wireless headphones.
This article first appeared in Electronic Design - www.electronicdesign.com