This may occur in the following situations:
The touch sensor on the headphones was covered unintentionally (for Truly Wireless headphones with touch sensors)
You can disable the touch sensor by changing the function of the touch sensor to None Assigned using the Sony | Sound Connect app.
- Open the Sony | Sound Connect app, and select My Device → Device settings → System.
- Select
Settings icon on the right side of the Change the touch sensor function menu.

- Select Not Assigned.

Adaptive Sound Control is set to On
Notification Tone When Switching is set to On
The notification tone can be disabled in the Sony | Sound Connect app.
- Open the app and tap Adaptive Sound Control to open the menu.
- In the Adaptive Sound Control Settings, tap the slide bar next to Notification Tone to disable this function.