Here in New York City, noise-canceling headphones are as important as comfortable walking shoes. I throw a set in my bag every morning to fight the sound of shrilly subway trains, noisy construction crews and that saxophone busker guy who always manages to find my subway car.

Muting the world might sound like bliss, but to walk around a busy city with only four senses in use is a dangerous game. They might be annoying, but some noises you actually need to hear, like a car horn or a siren.

Granted, some headphones like the Master & Dynamic MH40s have a manual pass-through button that mutes your music, but the industry needs to do better before someone actually gets hurt.

Amazon might be working on the first headphones that can save lives.

The company was just awarded a patent on July 19 for a noise-canceling headphone that automatically clicks off when it "hears" certain sound patterns, frequencies and even keywords like a name. The feature would allow the wearer to instantly tune back into his or her surroundings, and hopefully get out of the way of oncoming traffic.

A diagram in the patent application filed on July 25, 2014 shows an array of microphones built into the ear pads. I assume those could be used to listen to ambient sounds, similar to the way the Amazon Echo's Alexa is always aware of vocal prompts spoken around her. The description even talks about training the microphones to listen for a two-part audio command like "Hey Justin!"

That would make sense, given the inventors listed on the patent are two Amazon software engineers. One of them, Benjamin Scott, worked for three years on the Alexa Information team, according to his LinkedIn profile.

It's worth noting, though, the patent only protects the technology behind the invention and doesn't guarantee the headphones will actually be available to purchase anytime soon.

Still, as noise-canceling headphones continue to flood the streets, it's comforting to know that someone out there is looking out for our safety.