My dog gets really scared of the swear bleep noise and a specific ding sound effect. Also smoke detector beeps but those aren't often on shows. Since she started taking her anxiety meds it's not as bad, thankfully. But for real, it used to be that the bleep or ding would make her into a trembling mess.

Edit: I'm seeing now pet hate is synonymous with pet peeve. Oops. Oh well, I'll still leave my literal answer lol.