Game Interface/Constants remove value

[Derek0]

How do I remove the value (aka make it null, blank, nothing, etc.) of a certain field in the Game Interface and/or Constants windows?
I was trying to remove the "our ally's town in under siege" sound in the Game Interface because none of the allies have any towns that aren't invulnerable. Apparently if fighting around it causes it to say "our ally's town is under siege".

 

[SFilip]

you can most likely import a dummy sound that would replace it using the sound editor.

 

[Goauld]

Trigger action Unit Group - Pick every unit in (Units in (Playable map area)) and do (Unit - Turn alarm generation for (Picked unit) Off)

 

[Derek0]

I never noticed that trigger before. Thanks.