I think Bear nailed it. Currently their market penetration is low (I'm sorry but pressed for time and can't look it up but maybe 20% from memory) so have long runway of growth. 
the moat is becoming bigger as becomes industry standard so becomes effective monopoly with subsequent pricing power. 

no debt and cash in bank

margins are great and should expand rapidly

has similar product for video as a bonus which would be far bigger than audio

I don't own either currently as sold out some months ago but would also buy back in at more reasonable valuations which I am hopeful will occur in next few months.