Electronic muffs are ideal; most good ones (especially Peltors) actually magnify the low level sounds. They can actually allow you to hear game coming in when you normally could not.
In some cases, you can get away with shooting without ear protection--rifles without brakes, in open country. However, rifles with brakes and ALL hunting caliber handguns should be fired with hearing protection in place.
One word of advice: always take extra batteries with you for the protectors.
Hiding in plain sight...