What is a safe volume for me to listen to on my iPod touch?

The volume isn’t absolute. I own several mp3 songs where you have to turn the volume up or down. For example I downloaded a beautiful free sample from a music schools’ site and put it in a CD I use to listen to in my car. But I have to turn up the volume whenever that song plays. And I have to turn it down afterwards. Depends on whether you bought them, made them from a CD you own or have another source. The amplification is not always comparable. Also the heights are important. You ear can handle very loud bass sound but will be hurt by high tones of the same volume.

A generally good rule is to never turn so loud that you cannot hear normal speaking next to you. So for example if you are on a bus, then you should hear - (not necessarily understand every word) - people who talk to you or next to you even if they don’t shout. And you should also hear some of the traffic sounds.

You should keep the volume of your “Walkman” as low as possible. I have been listening to Walkmen for decades and still have good hearing. Use good quality headphones so that you can appreciate the quality of the sound at low volume levels. Repeatedly subjecting your ears to loud sounds will cause permanent, and irreversible hearing damage.