Assigning Audio to Freq

[TimeKilla]

Am wanting to find away to add custom audio into the Huey but can't figure out how to do it is there any doc's showing how to add sound when you click a switch like replacing that sound of it clicking with another.

 

Ideally, am looking for information on how to add a sound (radio chatter to a certain freq on the UHF am radio in the Huey), I am not looking to do it using mission editor want to do it by editing the files so when the Huey loads up and that freq is selected the audio will play.

 

Anyway point me in the correct direction?