There are certain apps that will make sounds from the internal speaker of the first generation iPod touch. All it can do, however, is little beeps. Mostly just the noises it makes when you plug it into your computer or your alert noises. Just beeps. No other sounds.
It's not a speaker in the conventional sense. It's a monophonic speaker, and a polyphonic speaker is required to make any noises besides single note beeps. Think of this speaker as pressing keys on an old phone that makes tones.