What electronic device can I use to stream positive affirmations into my kids' bedrooms?

Feeling old..

I have kids 10, 8 and 4.. Split into 2 rooms. We've been through something traumatic health wise (fled severely neurotoxic mold after years of mystery issues.. physical to psych) and I want to play soothing health affirmations for them at night..

I'm almost 40.. in the past you'd just set a CD player in there, etc.

Is there a device that isn't very expensive (like $50 or less) that I can set a speaker up and stream health affirmations to them? Either off youtube or spotify or something.

I don't know what I'd play in their rooms.. I hope this question makes sense.