How can I mute only no$gba?
Well setting the sound to ‘none’ in ‘Options->Emulation Setup->Sound Output Mode’ would accomplish this, however games like Pokemon wait for a sound to be played and when it’s set to ‘none’ that sound is simply not emulated and therefore the game appears frozen as it wait for the sound which never comes. So for those games you can’t set the sound to ‘none’ and therefore no$gba can’t be muted so your only solutions are to either live with it, mute your whole system or if you have Vista use it to mute only no$gba.