I've been going over similar forum posts and haven't found a fix for my problem.
Periodically my bluetooth audio goes silent and returns distorted to a normal level. This occurs on both my Sennheiser in-ear headphones and on my JBL Charge 5.
Audio example here: Stream bluetooth audio by aka.miki | Listen online for free on SoundCloud
This problem hasn't occured on windows, nor on other distros.
I'm using blueman, because connecting my devices was impossible with the ZorinOS bluetooth manager.
Welcome to the Forum!
Did You tried PulseAudio Control? If not open the Terminal and type sudo apt install pavucontrol and then open it and control the Settings and try Your Headphones again.
Unfortunately, this is not a volume issue, but a connectivity issue.
I'm using Blueman Bluetooth manager, and whenever I'm able to connect, the signal strength is weak. So that explains the reason fo the faltering sound, as illustrated in the audio snippet I provided.
Any suggestions on how I might address this signal strength? I'd blame this on my hardware, but this problem has only appeared since using ZorinOS. I'm completely in love with the look and feel of Zorin, so I'd hate it if this would be the reason to abandon it.
Maybe the Bluetooth of Your Machine is not good supported. You could try it with a Bluetooth Dongle.