Summary of PIEZO CONTACT MICROPHONE PICKS UP VOICE THROUGH BONE
Vesper's VA1200 is an analog piezoelectric MEMS voice accelerometer that senses voice vibrations through bone, rejecting ambient noise. It integrates MEMS, an amplifier, and a power regulator in a 2.9 x 2.8 x 0.9 mm reflow-compatible package, runs at 1.8 V (1.6–3.6 V) with ~160 μA consumption, and targets in-ear hearables, VR/AR headsets, smart-frames, and smart-glasses applications.
Parts used in the VA1200 project:
- Piezoelectric MEMS voice accelerometer (VA1200)
- Amplifier
- Power regulator
Vesper of Massachusetts is claiming high fidelity for a MEMs piezo microphone that picks up the vibration of the user’s voice through the skull.
Inside are the mems, an amplifier, and a power regulator.
Called VA1200, the company describes it as
“the world’s first analogue piezoelectric voice accelerometer. Unlike a traditional microphone, the VA1200 is completely immune to ambient sounds, and only picks up the user’s voice. It filters out background noises such as wind noise, music, subway noise and crowd noise.”
Specifications
- Nominal supply voltage is 1.8V (1.6 – 3.6V) and it typically consumes 160μA.
- Power supply rejection is -91dBA (217Hz, 100mVp-p squarewave, 100 – 2,400Hz A-weighted).
- Output impedance is 400Ω and output offset is 800mV.
- Operation is over -40 to +85°C
It comes in a reflow-compatible 2.9 x 2.8 x 0.9mm package, and applications are foreseen in in-ear hearable products. “Existing earbuds rely on mic arrays and algorithms to suppress environmental noise during voice calls,” claimed marketing director Roberto Condorelli.
VR and AR headsets, as well as smart-frames and smart-glasses are other potential applications.
Vesper also makes more conventional piezo mems microphones, except using broad cantilevers instead of membranes, arguing that these are less likely to clog with dirt and water.
Read more: PIEZO CONTACT MICROPHONE PICKS UP VOICE THROUGH BONE
- What is the VA1200?
The VA1200 is an analogue piezoelectric voice accelerometer that picks up a user’s voice via vibration through the skull and is immune to ambient sounds. - What components are inside the VA1200?
Inside the VA1200 are the MEMS transducer, an amplifier, and a power regulator. - What supply voltage does the VA1200 require?
Nominal supply voltage is 1.8 V and it operates from 1.6 to 3.6 V. - How much current does the VA1200 typically consume?
It typically consumes 160 μA. - What is the output impedance and offset of the VA1200?
Output impedance is 400 Ω and output offset is 800 mV. - What is the operating temperature range for the VA1200?
Operation is specified from −40 to +85 °C. - What package does the VA1200 come in?
It comes in a reflow-compatible 2.9 x 2.8 x 0.9 mm package. - What kinds of noise does the VA1200 filter out?
It filters out ambient noises such as wind noise, music, subway noise, and crowd noise. - What applications are foreseen for the VA1200?
Applications include in-ear hearable products, VR and AR headsets, smart-frames, and smart-glasses. - How does Vesper’s piezo MEMS approach differ from conventional microphones?
Vesper’s piezo MEMS use broad cantilevers instead of membranes, which the company says are less likely to clog with dirt and water.
