Muting Musescore's MIDI sounds when using external keyboard for note entry

Hi,

Can I mute internal instrument sounds when entering notes?

I hear my keyboard's internal sound when I strike a key then musescore's sound a bit later due to latency somewhere down the line. It's a bit distracting! ~ Ideally I'd have musescore's sounds just when playing a score back but not during note entry.

Thanks and apologies if this has been answered elsewhere, in which case I'll delete this post.

Thanks,

Sam.