3.3 Mic airtight structure design
The key to tightly matching the microphone rubber holder and the mechanism is a rubber ring. It can avoid receiving the pressure wave signal from the internal speaker of the product, which causes the DSP to process AEC poorly and makes the product have too many sounds during the phone calls. The echo or distortion phenomenon will decrease the communication quality. The design of the rubber ring mechanism is shown in Fig.3.1, and the air-tight isolation curve is shown in Fig.3.2
Therefore, to achieve airtightness of the rubber ring, the product structure must also give a certain pressure, so the rubber ring can fully interfere with the panel to achieve broadband airtight isolation performance. The AEC test items could pass easier when doing voice quality testing.