Hearing protection is vital for avoiding permanent damage from noise exposure.
Listening to anything at a high volume can permanently damage hearing over time. It's not just very loud, one-off noises, either; anything over 80dB (about as loud as someone shouting) can cause damage if we're exposed to it for long enough. Our hearing is precious and we owe it to ourselves to do everything we can to protect it.
Ear plugs are perfect for protecting our ears from quieter, sustained sounds and, in particular, are good for music concerts. Over-ear defenders provide much more protection than ear plugs, and are comfortable enough to be worn for long periods. You'll reap the benefit in a particularly loud environment, like a fireworks display, air show or motorsports event.