That is the theory, the real world does not always follow suit. There are good noise cancellation headphones and bad ones. The bad ones sound terrible and only mute the outside noise a little and eat up batteries. To be successful at canceling noise, everything must be in order. The lower the quality on any one component, the less effective the noise reduction will be. So how do they work? Basically the headset has a small circuit inside it that samples the outside noise. It then creates the exact opposite noise and plays it through the headphones along with the music. The noise from the outside plus the sound injected from the noise canceling circuit will cancel each other out at your ear resulting in music without the noise. How successful this is in practice varies wildly with different headsets. Another point worth mentioning is that high price doesn’t always mean better performance. Some very high priced headphones out there are simply terrible at noise reduction. You really have to put a set on and try them out before buying. This task is best done in a store, not trying out and sending back every headset in a catalog online.

Last, but of course not least, when evaluating noise cancellation headphones, keep in mind the estimated battery life. If you aren’t getting at least 20 hours or so on a single set of batteries, then you are going to need a lot of batteries. If the best set of headphones is a battery cruncher, though, I guess it’s time to get rechargeable batteries.

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Are there other situations might call for amplified headphones?  Sure, many computer sound cards have shoddy speaker drivers that have a low current output. They create a lot of distortion at higher volumes, sometimes over ten percent. Unfortunately, the distortion becomes quite noticeable unless you are just trying to drown out the noise of an overhead jet.  Maybe it’s a coworkers noise that you are trying to stifle. Nonetheless, having an amplifier in the loop can result in high sound levels with very low distortion. There is another another reason for having headsets with amplifiers in them. By having most of the work done by another amplifier, the device you are listening to can play without distortion and you can play the music at very high levels cleanly.

Will you be spending a small fortune for the extra batteries you’ll be needing. Well, amplified headphones do need batteries to power the amplifiers in them. Fortunately, most of these amplifiers consume very little power. So, playing time of 100 hours plus is not unreasonable. If you use your headphones during a commute, around an hour a day, that’s about three months on one set of batteries. That’s not bad performance. Personally I am a fan of rechargeable batteries and use them in all my headphones. I usually get a couple sets of them so that when one set is on the charger, the other set is in use.

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Built into the headphones are both amplifiers and sound processors. These sound processors recreate the missing cues that give the ears a sense of space. If they function properly, you are surrounded by sound. If you like watching movies but don’t want to disturb your neighbors or significant other at 1:00AM, then surround headphones may be for you. Movies sound fantastic because you can hear things coming at you from all directions. I have actually ducked when watching an action movie with surround headphones on. In fact, with the right movie, you’ll be ducking all about the room, in a good way.

Your probably wondering how much these things cost? Well, there are inexpensive units that work pretty well or you can go crazy and spend hundreds of dollars. You really need to get out there with your favorite movie and check out different models live at your nearest retail store. The more expensive units come with outboard Dolby decoder boxes and coaxial/digital inputs. These decoders do a great job of decoding the Dolby surround and mixing it into two channels for the headset that comes with the decoder. The less expensive units have everything built into the headphones. Unfortunately, these models tend to be quite heavy. The extra weight that these headphones carry due to the electronics on board may be something to consider. Extended sessions with the headphones can become uncomfortable if you are sensitive to that kind of thing. Again, as I mentioned before, test them out at a retail store before committing to buy. Nonetheless, whichever surround headphones you decide on, you will be astonished at the difference between them and ordinary headphones.

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Very small earbud bass headphones work by doing two things. First they isolate external noises. The part of the device that fits in your ear canal is made up of a special cellular foam which is sound absorbent and springy so it molds precisely to the inside of your ear. This airtight seal assures that the tiny vibrations produced by these earbuds is heard by your ears as very loud sound. Due to the geometry and proximity to your ear not much movement is needed from the diaphragm of the drivers to produce a high volume. Because of this, the sound is not distorted as it could be with traditional speakers. You should keep in mind that since you also won’t be able to hear yourself speaking with these, you will probably be yelling if someone asks you a question.

On the other side of the spectrum are the very large bass headphones. These headphones take the opposite approach and go large. Typically, they fit over the ears and seal out noise by covering and isolating the whole ear. The diaphragms of these headsets are very large. They produce heavy bass without even breaking a sweat. Unfortunately, they are not subtle. Wearing them to work is a bit problematic, especially if you are trying to keep a low profile. They stick out like a sore thumb and are also heavy so your ears might get a little tired after a while due to the cups pressing on the side of your head for long periods of time.

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So, what are some of technical details of typical surround sound headphones? Well, there are some models out there that actually have discrete drivers for all the components of a complete surround system. For those of you who are unfamiliar with surround technology, there is a middle front speaker called the center speaker for dialog. From side to side are the front speakers which supply the usual stereo sound that we are accustomed to hearing. Then there are two rear speakers for the surround sound and finally a dedicated sub-woofer for the low bass frequencies.

In some of the newer model headphones, all those speakers are actually present inside those large ear cups. If you take the cover off the headphones, you will see drivers for the center, rear, front and sub. All the drivers are spaced apart so you get enough separation of sound to emulate the sound you would hear from a home theater speaker system. Do these surround sound headphones work? Yes, according to the reviews they are extremely popular due to the fact that they actually work very well. They are pretty heavy though. To complete the package most headphones come with a multi-channel usb audio adapter. This adapter plugs into your usb port and drives all the channels of the surround headset. So, if you’re a serious gamer and want to experience the full effect of audio in your games then a pair of surround sound headphones may be just the thing for you.

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Let’s start with the advantages. The earbuds are small, light and compact. They go almost anywhere. Some even come with a case that looks like a compact but has a spool so you can turn it and the cord loops around the spool storing the cord without tangles or snags. Another advantage is that some sets have snug fitting foam pieces that are worn in the ear, dampening external noise. This is great as it really cuts down on noise so you don’t have to raise the volume to deafening levels. Earbuds headphones also have good bass response which is surprising considering their small size. All this fun does not come with some drawbacks, however.

What are the drawbacks of these type of headphones? Well for starters, they have to be put in the ear canal. Some people have small ear canals and some large ones. One size does not always fit all. For those who have larger canals, the ill fitting earbuds headphones will sound tinny. The escaping air volume will drain bass response away creating a shrill timbre. Also, some people find anything placed in the ear very uncomfortable. Indeed, there is also a chance of increased ear infections if you don’t clean and/or replace the foam pieces that go inside the ear. When putting the earbuds in your ear, it can take a bit of fiddling to get them in place properly. If you don’t get them in place, there goes the bass response, very annoying indeed.

OK, so if you break it down, there are two basic types of tv headphones, wireless and wired with a long cord. So what other features do they have that normal headphones don’t have? One feature they have is independent volume and balance controls. This enables you to adjust the volume right on the headset and you can make one side louder than the other. If you have a problem in one ear, using the balance control can allow you to listen to the television normally. Some headphones also allow you to switch to monophonic playback. When you have a television with one audio output, you may need this feature. Virtually all new televisions made today have stereo outputs so expect this feature to disappear eventually.

Wireless tv headphones come in IR versions and RF versions. What do these terms stand for? IR is short for infrared, the same technology that is used in your remote control. The benefit here is no radio waves are emitted, just infrared light. The downside to using this technology is you need a line of sight between the transmitter and receiver. If your headphones are under your pillow, you won’t hear the television. Also, if you walk to another room, to the bathroom, etc., the sound will disappear. RF stands for radio frequency and this type of transmitter works through walls and you should be able to hear your television anywhere in the house.

When I say my noise reducing headphones use passive noise reduction I mean that they use sound absorbing materials to dampen outside noise. There are no electronics involved. This means no extra batteries. It also means I look like a member of the space patrol. Yes, I mean that there are two giant black cups on my ears. Not an easy look to carry off, I assure you. Women don’t flock to guys wearing giant black headphones on their heads. That’s just me, your mileage may vary. Another great thing about them is I got what I like to call sweaty ear. Yep, those leather lined cups made my ears sweat after an hour or so. Yes, it is true. You also need to take a break because the fit is a little tight. When I say tight, I mean the cups pressed firmly against your head to maintain a good acoustic seal. This can give you a headache after a while. All these drawbacks aside, I loved those giant headphones because the sound was incredible, the bass astounding, and most of the outside noise was dampened. The noise dampening allowed me to keep the music volume fairly low which probably saved my hearing.

Noise reducing headphones also come in much smaller sizes. I found earbuds that have fairly large cushions. These earbuds are especially designed to mute external sound. They are small, sound great, and are very subtle. The drawback is that they are really picky about placement in the ear for best sound and noise reduction.

There are two major types of sound proof headphones. There are active noise cancellation units and passive units. The active noise cancellation headphones use noise canceling technology which requires its own power supply, usually one or two AA batteries. They have a microphone on the outside of the headphones which monitors the noise. This noise is fed to a small amplifier and it creates the exact opposite noise to what is going on outside. This “opposite” noise is fed into the headphones and the net effect is silence. The silence comes because the two sources of noise cancel each other out when they reach your ears. These type of headphones have two major disadvantages, the first being price and the second is the requirement for batteries to power the noise canceling circuitry. Some of them also don’t work all that well. You should try the headphones at the store before buying.

The passive type of sound proof headphones uses sound absorbing technology. This comes in the form of various sound dampening materials to isolate your ears from the outside. The ear cups typically fit all around the ear, surrounding it completely. This method can be very effective. The disadvantages of this approach vary. First, the headphones tend to be heavy. Second, the rubber surround on the ear cups has to fit well, so pressure needs to be applied. This can cause ear fatigue. Another potential problem is that you tend to sweat on the rubber surround. Last, but not least, these headphones are anything but inconspicuous, so if you are a commuter, prepare for some odd looks here and there.