When breaking or otherwise causing the sound effect for Grass breaking to play; it often sounds oddly "dissonant" or flanged. it is somewhat muffled, but in a way where it actually causes an unpleasant sensation of pressure in my ears. I really wish I knew a better way to explain.

to reproduce:

simply break a grassy block in vanilla 1.14 in creative mode and listen at moderate to low volume. if unable to reproduce; try again several more times, as the issue is not 100% consistent but happens very often. Does not seem to happen with any other blocks besides grass/leaves/vines/etc. 

Debug screenshot for better environment info...maybe.