"Arrays are slowly happening. You inherently get directionality and an increase in sensitivity but particularly with audio you want the elements in the array to be as far apart as possible, which is a countervailing drive."
But Crowley added that if the customer is prepared to have big die, says two centimeters on a side, or a big FR4-based component it is possible to think of a stand-alone array. Microphones in any case need a reasonable depth of housing to prevent damping of the microphone. Crowley said that customers with certain defense applications in mind have been approaching Vesper about arrays.
However, more general array developments are for the future Crowley said. Right now the company is focused on its zero-power listening microphone which can be used as a fundamental always-on sensor. "It allows the design to be power down completely except for a piezoMEMS microphone and a small listening circuit. Any noise will move the microphone membrane but a threshold can be set to wake up the rest of the MEMS ASIC and then to wake up the equipment. "It is proving of interest in smart speakers, smart remote controls, hearables," Crowley said.
This underlines that while the smartphone is the largest market for MEMS microphones it does not have the highest growth. There is some growth because gradually the number of microphones deployed in almost equipment is increasing. But the non-smartphone market for MEMS microphone is increasing at 50 percent per annum, Crowley said.
And that's another reason for Vesper to keep its focus on microphones.
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