Beat deafness is when someone can't hear or understand the beat in music. Imagine when you try to clap along with a song and you can't seem to do it right or stay in time. That might be how someone with beat deafness feels all the time when they listen to music. Even if the beat or rhythm is really obvious, they just can't hear it. It's like they're listening to a different song than what everyone else is hearing. This doesn't mean they can't enjoy music, but they might hear it differently and have trouble dancing or keeping a steady beat.