Music, cellphones and radio waves

Veronica
I was thinking of using my speakerphone instead of holding the phone up to my ear for calls, but I also don't know if it's okay to use earbuds instead, and to use earbuds to listen to music? I also wanted to play music for my baby once it gets to that point. What point is that at, and is this safe, and is there a safer device to do this with?