Heartbeat on ultrasound?

I'm curious if when you get an ultrasound done I know they can see the heartbeat but I'm wondering if you ask the technician if you can hear it if it's possible? Or only a doppler can hear the heartbeat. My next ultrasound I'll be 20 weeks exactly & I'm taking dad with me for the first time & he's never heard baby's heart before so just wondering if we can hear the audio or only see it. Sorry if this is a stupid question!