Update: In my opinion a slightly better approach is.
Individual Sound Volume by kathanon.
[url=https://steamcommunity.com/linkfilter/?u=https%3A%2F%2Fgithub.com%2Fkathanon%2FRimWorld-IndividualSoundVolume]https://github.com/kathanon/RimWorld-IndividualSoundVolume[/url]
The above mod allows individual volume control over most game sounds and throughout my tests has worked flawlessly.
The default alert sounds can sometimes be very harsh. This mod replaces the basic alerts sounds with higher quality variations that are frequency filtered. Unecessary high frequency and useless harmonics that contribute to tinitus are gone. Your ears will thank you.
Targeted Sounds:
AlertBasic.wav
AlertNegative.wav
AlertRed.wav
AlertYellow.wav
Happypop.wav
NegativeHealthEvent.wav
TaskCompletition.wav
