Microphone

MEMS microphones convert acoustic pressure waves into electrical signals using either capacitive or piezoelectric transduction. Capacitive MEMS microphones contain a thin diaphragm that deflects with sound pressure, changing capacitance relative to a fixed backplate; this capacitance change is converted to voltage by an ASIC. Wearable microphones typically have frequency response from 100Hz to 10kHz, sensitivity around -38 dBV/Pa, and signal-to-noise ratios of 60-70 dB. Multiple microphones enable beamforming for directional audio capture and noise cancellation. In health applications, microphones detect snoring patterns and sleep apnea events through acoustic analysis, monitor cough frequency and characteristics for respiratory health, enable voice-based interaction and commands, and can assess vocal biomarkers. Privacy-preserving designs process audio on-device, extracting only health-relevant features without storing raw audio. Ambient noise levels can also inform stress detection and sleep environment quality assessment.