Mic Airtight Structure Design
A rubber ring is the key to tightly matching the microphone rubber holder and the mechanism. It can avoid receiving the pressure wave signal from the internal speaker of the product, which causes the DSP to process AEC poorly and causes the product to make 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 airtight isolation curve is shown in Fig.3.2
Therefore, to achieve the rubber ring's airtightness, the product structure must also provide 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 more easily when doing voice quality testing.