Prolly somewhere like
7 Days to Die / Data / Config / sounds.xml (3297):
<SoundDataNode name="metaldestroy"> <AudioSource name="Sounds/AudioSource_Impact"/>
<Noise ID="0" noise="20" time="3" muffled_when_crouched="0.65" heat_map_strength="1.42" heat_map_time="90"/>
Huh, thanks. That's not where I would have started looking (I'd have thought it would be defined in the block.)