SPH0655LM4H-1 Cornell II SiSonic Microphone Knowles SPH0655LM4H-1 Cornell II SiSonic™ Microphone is a high-performance, bottom-port microphone with a single-bit pulse density modulation (PDM) output. The low-power microphone features SiSonic MEMS technology and consists of an acoustic sensor, a low-noise input buffer, and a sigma-delta modulator. The multimode digital microphone features excellent wideband audio performance and RF immunity. Knowles SPH0655LM4H-1 Cornell II SiSonic Microphone applications include cellphones, smartphones, laptop computers, sensors, digital still cameras, and portable music recorders.