Tuesday, November 16, 2004

Noise Cancelling Headphones!


I bought a new pair of headphones in Denver airport on my way home on Sunday. I'd been considering getting these for a while and then there they were right before me in the departure lounge. I got a pair of Bose QuietComfort 2 Acoustic Noise Cancelling Headphones. They are really cool. I'm so blessed to be able to afford them. They worked really well on the plane. I was able to cut out all the background noise of the engines and I was also able to watch the movie (I, Robot) with no outside noise. I'm very pleased with them. It's not often I buy something so extravagant for myself.
 

5 comments:

Sgt Steve said...

Dude, those thing sound intense. Will they work for DJ's?

Andrew G said...

good for u man

Andrew G said...

you prob. don't want to lend them to Steve tho (unless he promises he won't be wearing them on his dirt bike)

The Ken said...

Well, Sarah, I'm glad you're taking your tongue hygiene seriously now. I don't know how mankind survived so long without "The Tongue Scraper". Interestingly enough, it's raised a question in our house of whether such a thing is too gross to leave lying around on the bathroom counter. I reckon it's no worse than a toothbrush. In fact, it's probably cleaner. A toothbrush has all those bristles which probably retain some pasty-ming combo.

Anonymous said...

Greg said:

Noise cancelling headphones are cool. Ones that encapsulate the ear are more effective than ones that don't. The premise behind it is that each headphone has a mic on it that picks up sound that would be reaching your ear. So if you put on one headphone, what you actually hear is a live mic playing into the small speaker that goes next to your ear.

One of those signals gets switched out of phase with the other, (so when the waveform is going "down" on the left ear, it's going "up" in the right ear). By the time that reaches your brain, you think that you are hearing nothing at all: just a "flatline".

Whatever sound penetrates the headphones from outside is still audible, as it is "in phase".

This means that you can then plug "in-phase" music/audio into the headphone signal in both ears, and that's all your ears "hear".

Your ears are still getting the full volume of sound fired at them, though, so they are not adequate "ear defenders". Amazing how tranquil they can make you feel, though, especially on a plane.

Recording engineers have used this "out of phase" technique for recording: essentially, if a singer doesn't like using headphones for their guide track, they get two out-of-phase speakers either side of the singer: equidistant from the mic, but inequidistant (is that a word?) from the singer. So to the singer can hear the sound, but the mic hears very little of it. It's impossible to make it completely silent, due to things like reflections of soundwaves, but it certainly means that the backing track is a lot quieter when it reaches the mic.

Well done at your purchase of such a geeky and yet immensely practical object.

greg