Earbud, earphones, IEMs
Earphones sit in your ear canal. Earbuds rest on the conch, just outside the ear canal. Earphones deliver a more secure fit, resulting in better external noise isolation and potentially superior sound performance.Earphones also often offer a selection of 'sleeves' to help achieve the best fit. Consequently, earphones tend to fare better for sports use and noisy environments such as public travel. However, some people find the earphone design's snugness and isolation effect off-putting.
Some earphones are referred to as in ear monitors (IEM)which is a reference to their design being intended as a reference point to monitor live broadcasts and performances (you’ll often see presenters or performers with fitted earphones of this nature). Some companies have a considerable tradition in making earphones for professional use and employ the same thinking in their domestic earphones. There’s no binding set of standards that defines an IEM but they should offer an accurate and unembellished performance that reflects the source and recordings.
The overwhelming majority of earphones will make use of one of these driver types. Dynamic driver models use a tiny version of a normal speaker driver in each enclosure. The advantages of such a design include relative simplicity (often making the housing itself smaller) and decent bass response.
Armature headphones use an electronic signal to vibrate a tiny reed that is balanced between two magnets inside a tiny enclosure. The motion of the reed is transferred to a very stiff aluminium diaphragm. They are sensitive and incredibly responsive but can lack bass extension. This means that many high end earphones will use more than one- and sometimes into double figures of- armatures to improve the frequency response. A small number of models combine both dynamic and armature drivers too.
Silicone rubber is the most commonly encountered material for earphone domes and it works well, allowing a little deformation to fit the ear canal. An increasingly popular alternative is Comply, a memory foam type material that can be compressed between your fingers before it expands to fill your ear canal. Some people find that comply can be a little hot and uncomfortable and most manufacturers supply both.
An option on some high end earphones is custom moulding. This involves taking a mould of your ear canal and encasing the drivers in mould that perfectly fits it. In terms of comfort and noise isolation, this is very hard to beat… but selling them later on can be tricky.
In essence, balanced drive is a headphone amplifier design scheme that delivers 'balanced' equivalent and opposing (i.e., negative/positive) audio signals independently to each side of the headphone driver coils. This both increases the voltage available to the driver while lowering distortion and reducing crosstalk (the unwanted transmission of audio from one channel to another). To achieve this, balanced headphones will need to use either a 2.5mm or 4.4mm four pole jack or a single four pin XLR or twin three pin XLR sockets and have access to a balanced source to supply the signal.
The single most important thing to take into account when choosing whether to ditch the cable is that only a wired earphone will successfully reproduce the full bandwidth of a lossless (CD sized) signal let alone a high resolution one. If you can cope with having a cable on your person, wired headphones- even very cost effective ones- can comfortably outperform wireless ones.
In busy spaces though, wireless earphones reduce the chance of you snagging that cable and the notional limitations in performance are going to matter less. Throw in that many wireless models have noise cancelling to drown out those awful early morning conversations at least one of your fellow commuters insists on having and they start to make a lot of sense.
True wireless earphones do not have cords or wires connecting the buds. Everything, including the battery, controls and mic, is built into the housings of the earphones and they receive audio over Bluetooth. This means that each earphone needs its own battery which places limits to how large that battery can be which in turn means that earphones can’t match the battery life of full size headphones. To partly get around this, manufacturers put an extra battery in the case which can charge the earphones when you put them away.
These are not to be confused with wireless earphones, which feature a cable connecting the left and right buds. This is less elegant but can give longer battery life and works better for exercise as the earphone won’t fall straight on the ground if they fall out of your ear. A very small number of earphones can swap between a wire for connection to another device and a wireless yoke.
Noise cancellation headphones use active noise cancellation (ANC) technology to block out background sounds. Noise-cancelling designs rely on electronics, unlike noise isolating models, which depend on a physical structure to defeat ambient interference. Many true wireless earphones use a pair of microphones to compare noise levels inside and outside the enclosure which allows them to dynamically adjust the amount of noise cancelling they need to apply.
Bone conduction technology has its origins in the hearing aid market. The tech doesn't rely on the eardrum but instead sends information by routing vibrations from the cheekbones directly to the cochlea. When it comes to audiophile performance, bone conduction technology has a way to go. Still, for those looking to remain audibly aware of their surroundings, such as cyclists and runners, bone conduction headphones leave the ear canals open to the outside world.