Deaf

Deaf is a disease which disables the player character's hearing, for example, smashing something won't say "From the (direction) you hear whump!" Deafness can be gained when a flashbang detonates in 8-square radius or nearer or sometimes when the character hears a noise with volume over or equal to 150. In both cases, the duration is based on distance to the source of sound and its volume. In the latter case, the duration cannot be longer than 40 turns, however it appears the duration can stack, deafening you for hours.

Deafness can be prevented by Enhanced Hearing bionic.

When deaf you cannot talk to NPCs, and you risk strangers becoming hostile upon meeting.

Players can be in significant risk of long lasting deafness if they are in a burning building, or any collapsing buildings, since the sounds of the collapsing can be really loud and stack. You could use ear plugs to avoid deafness, but do not forget to take them off when you do not need them anymore.