How to do when i shoot to the head it will play a sound

I need help with somthing im working on…

How to do when i shoot to the head it will play a sound i want…
thanks for the helpers:)

[lua]hook.Add( “ScalePlayerDamage”, “Boom”, function( p, h, d )
if ( h == HITGROUP_HEAD ) then
p:EmitSound( “boom.wav” );
end;
end );[/lua]

Thank you