Is the problem only when you're playing music, or is it with all sounds whatsoever?

Windows, Macintosh, or Linux operating system?

I'll assume Windows real quick and throw this out for giggles. Open up the Run command (Windows Key + R) and type sndvol32.exe into the prompt. It will open your volume control panel, complete with extra settings aside from just a volume bar. Make sure your other forms of output aren't turned down. Everything to the right of the master should probably be maxed out, and then you can use master volume for control.

Most of the time, people will get the Wave volume turned off somehow and won't be able to hear sounds any more. It's a common error.

If everything is fine in there, check the speakers. You said it's a laptop, so if the speakers have blown out, or the sound chip (it likely has onboard sound, which is a chip on the motherboard) has burned out, you'll need replacement parts.