What's with Apple's intermittent voice?

Apple's intermittent sound may be due to the following reasons:

1, the Apple handset is blocked by foreign objects, or the internal hardware of the handset is damaged, which can be detected by headphones;

2. Apple's mobile phone operator's network is not smooth, so you can change to another operator's network test;

3. Apple's mobile phone system is disordered, resulting in intermittent voice of Apple's call, which can pass the brush test;

4. The audio IC on the motherboard of Apple's mobile phone is damaged, resulting in intermittent voice.