a) Ensure volume is set to maximum through Mobile Phone itself
b) Ask CX to use suitable size of eartips and wingtips
c) Ask CX to use other music APP/music player as different songs/videos app have different audio quality with different Mobile Phones
d) Ensure cleaning of eartips and validate this by image and ask customer to clean it carefully
Steps to Reproduce Solution
Control the volume from Mobile Phone
CX can find different size of eartips and wingtips in accessories box
Different music APP customer can download from APP Store
Suggest CX to not use any sharp object to clean ear tips