Earphones range from the very small and cheap to the very large and bulkyFor the most part, everyone already knows what earphones (also called headphones) are. But what is the difference between the pair included with your snazzy new MP3 player, and the expensive ones you see in the electronics store? Well, let’s find out.

One thing that few consumers know is that the quality of sound output varies little from MP3 player to MP3 player. While features, capacity, and lots of other factors contribute to the choice you make, the sound quality from one halfway-decent machine to another is negligible. So, the difference between an average personal music experience and a superb one is almost entirely in the ‘phones.

The difference between expensive headphones and inexpensive ones is that most high-end models have separate drivers for high and low frequency sounds. Called woofers (for low frequencies) and tweeters (for high frequencies), these two individual components produce the notes that your ear interprets as a single sound. There is also a difference in the way that the musical signal is played. There is a misconception that high quality earphones have a flat response setup—this means that the drivers within the headphones don’t have any additional boost to either the high or low ends of the musical signals. This simply isn’t true. Many, many high-quality headphone sets have treble or bass boosts for those individual drivers.

This is because today’s more popular music often relies significantly on the bass and low-end frequencies to drive the song. This in turn means that most consumers prefer headphones that provide a little oomph in your bass signal. Because this will inevitably shift the audio balance toward the low-end frequencies, those same quality headphones with the bass boost will often have high-end boost for the tweeters as well, for well rounded sound quality.

Here’s a list of often-used headphone and earphone terms.
Earphones—Audio drivers housed in a small case that are placed in the ear and have no headband.

Earbuds—The type of earphones that often come with MP3 players such as the Apple iPod. They generally fall out easily. They are usually not equipped with bass boost, and are not very expensive.

In-Canal Earhones—You can tell these by their distinctive shape. That special shape allows the service end of the earbud to fit snugly into you ear canal and create a seal. Along with a more secure fit, balanced sound quality, and better bass, this design is sometimes equipped with noise reduction or cancellation technology.

Headphones—Audio drivers in earpieces that sit on or outside the ear and have either a headband or a neck band for stabilization.

Circumaural Headphones—These form a seal around your entire ear. They are popular with DJs, professional musicians, and those audiophiles that aren’t interested in blending in.
Noise canceling headphones like these are pefect for long flights or trips
Noise Canceling—This technology uses active circuitry to block out or counteract ambient noise around the user. This makes for a very private listening experience…but don’t drive with headphones like these (or any other) on your head!

Noise Isolating—These types of headphones don’t actively reduce sound, but they do reduce distractions by creating seals around or in the ear. This can cut down on the ambient noise around you just as easily as noise canceling models.

Maximum SPL—This measurement tells you how loud your headphones can get. Remember, 120dB is where your ears should traditionally start to hurt, but 90dB is where permanent hearing loss begins. So don’t turn these babies up too high!

Frequency Response—denoted in KHz, the frequency range indicates the variety of frequencies that an earphone’s drivers can reproduce without a significant drop in volume level.

Impedance—This term refers to the resistance that the headphones produce to the alternating current coming from the player. This measurement is denominated in Ohms.