With Optifine there is no single Particle button. Instead there is an Animations menu where you can enable/disable each category independently.I mean the actual particles button. If you set particles to off rain no longer lakes noise. It's a trick youtubers used in the days before 1.7 when there was no volume levels for specific things
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Could be the way Optifine handles the animations did something to the sounds. Dunno.
EDIT: actually changing it from "minimal" to "All" or "Decreased" did the trick