So basically when I tried to explode some netherrack to find some ancient debris, I found this bug where the evaporate sound of water in the nether would play indefinitely.
Steps:
1. Get tnt
2. Ignite tnt in the nether
3. While the tnt is primed, place down water.
4. Once the tnt exploded, you have an infinite sound source.
I don't know if the tnt is part of the problem and if it's just the water, but I found out this way.
Please provide a small clip of this occurring with F3 debug screen enabled and subtitles enabled.