What's the difference between ear buds and headphones?

Headphones connect with wires or a wireless signal to a source such as an audio amplifier, radio, CD player, mobile phone or portable media player. There are on-ear and over-ear versions. Earbuds, sometimes known as earphones, are small speakers designed to fit directly into your ear. There are two varieties here. Earbuds rest on the outer concha ridge of the ear, located in the center of your outer ear. In-ear models fit into the ear canal.

What is a safe decibel level for headphones?

Sound levels of up to 85 decibels are considered safe.

How long is a reasonable amount of time to listen to headphones?

Eight hours per day or 40 hours per week is what's recommended by the scientific community.