Are noise cancelling headphones effective at all when firing a gun?

Maybe a better question would be: “Are noise muffling earpieces better than noise cancelling headphones when it comes to firing guns?”

Former Bose headquarters employee here. Noise cancelling headphones can’t respond quickly enough for gun firing purposes. They don’t work that way. OTOH, many quality noise cancelling headphones are also superior at passive sound reduction as well. Bose makes military and commercial headsets that are great at both active and passive sound reduction. OTOH, you could just get cheapo ear plugs. They are much better than nothing.

I do earplugs or muffs on an outdoor range, plugs and muffs on an indoor range.

I usually use “electronic muffs”. They amplify ambient sound so you can hear conversation and range commands but reduce loud sounds to a safe level. There are two types. One type cuts off the sound so it sounds dead instead of loud. The second, and better in my opinion, reduce the loud sound to a safe level. So it never cuts off the sound, but drops the volume to a safe level. These seem to be the most popular.

Most noise cancelling headphones in my experience work via the principles of destructive interference of the sound waves, meaning they produce a sound to cancel the sound you don’t want (i.e. not what you’re listening to) dictating they’d probably not be able to respond quickly enough. Earmuffs or plugs are good here. However for filtering of plain ambience the headphones are probably better (unless you want to get those professional reusable musicians ear plugs of course).

I’m a little confused: why would noise-canceling headphones not be able to respond quickly enough? Isn’t the speed of sound a constant? What does it matter if it’s the sound of a gunshot or, say, the sound of an amplified guitar. I would think the problem would be more that the headphones couldn’t produce a loud enough phase-inverted signal to result in adequate destructive interference. But I’m by no means an expert on the matter.

Because destructive interference (as you seem to know) requires a phase inverted signal. To produce the precise signal to cancel out the boom it needs to first hear the signal, register it, and THEN produce the cancelling signal. It’s only a short timespan but so is the sound of a gunshot. It may muffle the end a bit but by the time it establishes the phase it needs to cancel the noise has already passed.

To add on to what** Jragon** said, noise canceling works best when the sound is continuous. In fact, and I’m sure Shagnasty will correct me if I’m wrong, but the first headphones produced were designed/marketed for the constant hum of an airplane’s engines.

That’s correct, they work for constant hums. It works really well on my train commute, but when I get off at my train station and another train goes by, the invertion is too late.

The rise time from silence to hazardous levels is far quicker for an explosion than it is for a guitar or a noisy machine.

If you’re looking to buy hearing protection to use while shooting, look for the word “tactical” in the product literature. The $20 earmuffs available at the hardware store are fine for protecting your ears against things like the steady scream of a woodworking router or the drone of a lawn mower.

Fortunately, tactical protection is not expensive - we just bought some Peltor tactical protectors for $70. They’re pretty clever - on their own, they blot out just about all sound. Turn up the volume, and you’ll be able to hear conversations and more importantly, commands from the range officer. But they’ll still keep the gunshots to a safe volume.

If you don’t mind being so closed off from the world that people have to wave at you to get your attention, foam earplugs with the above-mentioned hardware store earmuffs will do the job as well.