We run every pair through a rigorous testing process over several days or weeks. That includes playing them in all sorts of scenarios — be it on a bus, in the listening room, or at the office — and playing back from a wide array of sources. We know most people use their headphones with a smartphone, often with lower-quality MP3 resolution tracks, so we do, too.
Hearing risk from headphones' use also applies to workers who must wear electronic or communication headsets as part of their daily job (i.e., pilots, call center and dispatch operators, sound engineers, firefighters, etc.) and hearing damage depends on the exposure time. The National Institute for Occupational Safety and Health (NIOSH) recommends sound exposure not exceed 85 dB(A) over 8 hour work day as a time-weighted average. NIOSH uses the 3-dB exchange rate often referred to as "time-intensity tradeoff" which means if sound exposure level is increased by 3 decibels, the duration of exposure should be cut in half. NIOSH published several documents targeted at protecting the hearing of workers who must wear communication headsets such as call center operators, firefighters, and musicians and sound engineers.
We use a commercially-available Bluetooth high-def interface with an S/PDIF output to test the Bluetooth output of four flagship phones. This way, we’re able to record test signal output and compare the datasets with our in-house analysis software. We kicked the tires on a 96kHz/24-bit test file to see how Bluetooth handled high-bitrate music, as well as normal 44.1kHz/16-bit files to see how each codec treated CD-quality streaming audio. We then measured the recorded sample against the original file. We used both lograrithmic sine sweeps, and complex signals like square waves in order to provide a more realistic set of tests for how people actually use Bluetooth headphones.
Until now, the best true-wireless earbud features like noise cancellation or hands-free access to voice assistants were something you could only have if you spent well over $200. So when Amazon introduced its Echo Buds for just $130 with onboard Bose active noise reduction, IPX4 water-resistance, hands-free Alexa access, and a customizable fit, our only question was: Do they sound good?
Dale: There are so many types of amplifiers (and DAC’s with amplifiers) that there is no shortcut for studying all of the options, unless you settle for the most generic approach. Important things to consider are power – if you don’t have enough power for your headphone and the dynamics in the music, clipping will result. Sometimes the clipping is “soft” and not readily noticed, but eventually you would discover that much of the detail goes missing or gets veiled with limited dynamics. Another consideration is whether to use a DAC, which may be a separate DAC or built into the same enclosure as the amp. Most DACs will improve the sound over the DACs that are built into computers, but when a DAC is available to replace the DAC built into most cellphones and low to mid-priced music players, you can usually expect a much greater improvement.
The rule that I use is that the bigger the size of the headphone, the bigger the need for amplification. Of course factors like driver sensitivity and impedance will matter, but the general rule of thumb is, use a dedicated headphone amplifier for a full size headphone. Even a portable amplifier can be enough, depending on the type of the headphones.
Garbage in = Garbage out (GIGO) is a popular phrase used to emphasize the importance of a good source. This can be the soundcard in your laptop, the quality of your portable audio player, or the CD player you’re using for music listening. Those fall into the “Source” category. The better your source is, the better the sound will be at the headphone end. This is why we are seeing more and more audiophile digital audio players (audiophile DAPs). They are expensive but they sound good.
I see, yes, but that should serve as an important lesson – the soundstage is not real in the same sense as actual tones, bass, treble, whatever. Soundstage is a perception that’s based on many factors, and here’s a challenge for you: You should be able to find some music tracks that have better soundstage on one headphone, and other tracks that will be better on the other headphone. Most of the time it will be just one way, but when a closed headphone beats an open headphone, I expect the open headphone will still show an advantage on some tracks. Your hearing perception could be tricked by simple things like a recess or emphasis in certain frequency ranges, or even phase shift when more than one driver is in the cup.
Magnetostriction headphones, sometimes sold under the label Bonephones, work by vibrating against the side of head, transmitting sound via bone conduction. This is particularly helpful in situations where the ears must be unobstructed, or for people who are deaf for reasons that don't affect the nervous apparatus of hearing. Magnetostriction headphones though, are limited in their fidelity compared to conventional headphones that rely on the normal workings of the ear. Additionally, in the early 1990s, a French company called Plasmasonics tried to market a plasma-ionisation headphone. There are no known functioning examples left.
Portability can mean many things, such as appearance in public, having a secure fit so the headphone doesn’t shift off of your ears, amount of isolation from ambient noise (including active noise canceling), whether the headphone can be worn around the neck when not listening or it requires a carry case, and when extra amplification is required, whether a suitable amp can be found that’s OK to carry along with the portable music player.
Circumaural headphones (sometimes called full size headphones or over-ear headphones) have circular or ellipsoid earpads that encompass the ears. Because these headphones completely surround the ear, circumaural headphones can be designed to fully seal against the head to attenuate external noise. Because of their size, circumaural headphones can be heavy and there are some sets that weigh over 500 grams (1 lb). Ergonomic headband and earpad design is required to reduce discomfort resulting from weight. These are commonly used by drummers in recording.
The thermoacoustic effect generates sound from the audio frequency Joule heating of the conductor, an effect that is not magnetic and does not vibrate the speaker. In 2013 a carbon nanotube thin-yarn earphone based on the thermoacoustic mechanism was demonstrated by a research group in Tsinghua University. The as-produced CNT thin yarn earphone has a working element called CNT thin yarn thermoacoustic chip. Such a chip is composed of a layer of CNT thin yarn array supported by the silicon wafer, and periodic grooves with certain depth are made on the wafer by micro-fabrication methods to suppress the heat leakage from the CNT yarn to the substrate.
Preferences for the length of headphone cables vary for portable users, especially depending on where you prefer to wear your device: a backpack or a pants pocket necessitates a longer cable, while you'll opt for a short one when wearing a player on a neck lavalier or an armband. But a cable length at either extreme need not be a fatal flaw: extension cables can lengthen those that are too short, and cable wraps can tighten up ones that are too long.
The QuietComfort 20 headphones have been around for years and years; and they’re essentailly an in-ear alterative to Bose’s QuietComfort 25. They offer the same great active noise-cancellation that the company is known for, just in a traditional wired and in-ear form factor. The QuietComfort 20 can also be switched to an “Aware” (aka ambient) mode, so you can better hear the world around you.
The design is not mechanically stable; a slight imbalance makes the armature stick to one pole of the magnet. A fairly stiff restoring force is required to hold the armature in the 'balance' position. Although this reduces its efficiency, this design can still produce more sound from less power than any other[clarification needed]. Popularized in the 1920s as Baldwin Mica Diaphragm radio headphones, balanced armature transducers were refined during World War II for use in military sound powered telephones. Some of these achieved astonishing electro-acoustic conversion efficiencies, in the range of 20% to 40%, for narrow bandwidth voice signals.
Dale: The examples listed above are good general rules, but there also are so many exceptions and in-betweens that it also could be better to understand what is needed for your music, so you can narrow the search to the most appropriate headphones. For example, you may have heard that Classical music is a particular genre, but within that ‘genre’ are many very different types of music. Chamber music or pipe organ music may benefit from a headphone that’s highly detailed in the treble (a headphone that some users might say is bright), while harpsichord music and music that has a lot of strong trumpet sounds might be better served with a more rounded or softer treble.
The Galaxy Buds produce exemplary audio quality packed into a pair of unobtrusive earpieces, complete with easy-to-use touch controls for playback, volume, and skipping tracks. According to Samsung, they have a 6-hour battery life and come with a powered carrying case that will recharge the earphones for up to 7 additional hours of playback on the go. The case itself can be charged with a wireless charging mat, and it’s particularly small compared with the cases that come with many true wireless models.
A balanced armature is a sound transducer design primarily intended to increase the electrical efficiency of the element by eliminating the stress on the diaphragm characteristic of many other magnetic transducer systems. As shown schematically in the first diagram, it consists of a moving magnetic armature that is pivoted so it can move in the field of the permanent magnet. When precisely centered in the magnetic field there is no net force on the armature, hence the term 'balanced.' As illustrated in the second diagram, when there is electric current through the coil, it magnetizes the armature one way or the other, causing it to rotate slightly one way or the other about the pivot thus moving the diaphragm to make sound.
Noise cancelation for kids? Doesn’t that mean they’ll ignore their parents even more often than they already do? Perhaps, but it’s a risk worth taking if it means your kids’ hearing will be protected over the long-term. That’s exactly the premise behind the Puro PuroQuiet headphones. Not only are they wireless and great-sounding, but they also come equipped with a software limiter that keeps the volume at or below 85dB, which is considered the maximum volume that children should be exposed to for prolonged periods. The noise-canceling feature means they’ll actually be able to listen to lower (therefore safer) volumes.
If you’re buying wireless headphones, keep a spare pair of wired headphones around in case the others run out of battery. Wireless headphones are definitely the future, and the convenience is a huge benefit, but they rely on battery power to work their magic, and batteries run out. If you’re going to be in a place where you won’t be able to recharge your wireless headphones, consider keeping a backup wired pair with you so the music never has to stop.
These headphones hush ambient noise by creating anti-noise that obviates the noise at your ear. They don't eliminate the outside world, but the better models significantly reduce the whoosh of airplanes' air-conditioning systems. Noise-canceling headphones come in all forms, from full-size to earbuds. Since you no longer have to crank up the volume to overcome background noise, this type of headphone lets you listen at lower levels, which leads to reduced ear fatigue. You'll also hear more low-level detail in your music.
In the professional audio sector, headphones are used in live situations by disc jockeys with a DJ mixer, and sound engineers for monitoring signal sources. In radio studios, DJs use a pair of headphones when talking to the microphone while the speakers are turned off to eliminate acoustic feedback while monitoring their own voice. In studio recordings, musicians and singers use headphones to play or sing along to a backing track or band. In military applications, audio signals of many varieties are monitored using headphones.