I expect that enabling custom categories could lead to this being useful in ways that you'd never expect. For example, people with misophonia HATE the sound of

I expect that enabling custom categories could lead to this being useful in ways that you'd never expect. For example, people with misophonia HATE the sound of people chewing loudly. It's not uncommon (the misophonia subreddit has 8,000 subscribers). I'd love to use your filter to mute the audio (and simultaneously turn on the subtitles, if possible) when there are misophonia triggers in movies. People with misophonia are already interested in movie warnings for this (e.g. the subreddit had several high profile warnings about the triggers in The Martian). If misophonia is a possible useful application of custom categories, there might be many others.