Sony WFC700N/B WF-C700N Truly Wireless Noise Canceling in-Ear Bluetooth Earbud Headphones

If you feel the size of the earbud tips does not fit your ears, change the earbud tips. When changing the earbud tips,

try the earbud tip sizes in order from the larger ones to the smaller ones. The most suitable size of the earbud tips for

left and right ears may be different.

Check that you are wearing the headset properly in your ears.