The sound warning me that it's my move is not loud enough

I only play 90 minutes + 30 seconds games. There aren't many people who want to play games this long, so when I create a challenge I have to wait on average 30 minutes before a game starts. This is not a problem for me, because during this time I just watch Youtube videos (or Netflix, Amazon Prime Video, Apple TV). The problem is that when a game starts, "sometimes it doesn't make any sound to warn me, and sometimes it does make a sound but the sound is nowhere near loud enough for me to hear it, the sound gets drowned in the sounds that the Youtube videos make", and so the game gets aborted.

When I am playing a game, when it's my opponent's turn to move, I watch Youtube videos while my opponent is thinking, and when he makes his move, "sometimes it doesn't make any sound to warn me, and sometimes it does make a sound but the sound is nowhere near loud enough for me to hear it, the sound gets drowned in the sounds that the Youtube videos make", so this makes me lose time on the clock and it makes my opponent wonder whether I have abandonned the game.

How do I fix this problem? Is there a way to make the sound much louder and last longer than just a single bip? Is there a way to get a notification pop up on my screen instead of just the sound?

I use Safari. Perhaps there is a Safari extension that would solve this problem?

I don't play on chess.com but this problem is not specific to one single chess website, I would encounter this problem on all chess websites.