Sounds Excellent! Vesper Develops a MEMS Microphone with a Difference

The huge popularity of ultra-mobile devices, such as smartphones and tablets, has driven demand for miniaturized electronics, and this has encouraged the use of relatively tiny MEMS (microelectromechanical systems) microphones.


Boston-based Vesper is pioneering a new type of MEMS microphone, a piezoelectric MEMS microphone, as opposed to the more conventional capacitive MEMS microphone. Vesper claims this enables a higher signal-to-noise ratio (SNR), for greatly improved audio quality and sensitivity.

In June 2015, Vesper launched VM101, its first piezoelectric MEMS microphone, claiming an SNR of 68 dB, or double the performance of high-end capacitive MEMS microphones, typically rated for an SNR of 65 dB.


The secret is in the design of the transducer. The transducer of a capacitive MEMS microphone contains a diaphragm. When sound waves hit the diaphragm, corresponding audio signals are created. In the case of Vesper’s piezoelectric microphone, the pressure waves cause piezoelectric cantilever structures to move, resulting in audio signals according to the piezoelectric effect – audio signals with a significantly enhanced SNR.


Vesper’s piezoelectric MEMS microphones aim to make a vast improvement in call quality by implementing ambient noise cancellation – and in the process potentially revolutionize the user experience. They can also capture sound at greater distances.


But Vesper’s vision for the technology goes well beyond simply clearer talk. Vesper sees input, on ultra-mobile devices, moving away from touch to voice. Indeed, a wide range of devices will become increasingly voice activated, including TVs and other consumer electronics items, plus the sensor and wireless-based control systems that will be key to the functioning of the smart home.


In these scenarios, a wide range of applications stands to benefit from the enhanced selective sensitivity of Vesper’s piezoelectric MEMS microphones. The microphones will be able to distinguish between the sounds that are to be heard and recorded and ambient noise in the background, enabling what Vesper calls ‘audio zoom’. A smart TV, for example, could be controlled in this way, by voice, rather than through the use of a conventional ‘remote’, even when there’s typical noise in the background – a dog barking, music playing, and so on.


Wearables, a relatively new type of device, also stand to benefit from voice activation and control, and at just 3.35 x 2.50 mm, VM101 has the miniature dimensions wearables demand. But wearables are also subject, potentially, to quite high levels of shock. Will the Vesper microphones take the beating? The company says they will. They are designed to be shockproof, waterproof and resistant to dust and particle contamination.


VM101 is currently sampling, with production volumes slated for Q4 2015. For further information, visit Vesper on the web at