1. Switch to another machine and test whether the same situation occurs. If not, there may be a problem with the headphone port of the first machine or the headphone plug is not fully inserted.

2. Check whether the headphone wire is aging and damaged. On the premise that the audio source is connected, start to bend back and forth slightly from the outlet position of the plug. If there is sometimes sound and sometimes no sound, it is determined that the headset is damaged.

3. Whether the test music has only background sound but no voice, change the track.

It is more likely to be the second case.