Whether they're in-ear, on-ear, or over-the-ear, PCMag puts headphones (technically earphones for the first group) through the wringer to find out which sound best. But what exactly does that mean? Here's how we test every pair we review.

Headphone Types and Design

There are several different types of headphones and earphones, and it goes much deeper than just earbuds and cans. Circumaural, or over-ear, headphones have large earpads that completely cover the ears and are generally the most comfortable. They're also excellent for isolating sound. Supra-aural, or on-ear, headphones have smaller earpads that just press against the ears; they're lighter and block out less noise. Earbuds are small speakers that fit into the outer ear, but are not inserted into the ear canal. In-ear headphones are also small like earbuds, but have soft rubber or silicone tips that are inserted into the ear canal and can block out outside noise like over-ear headphones.

Fit is a very important factor in how we judge headphones and earphones. For on-ear and over-ear headphones, we evaluate how they feel on the head and if they remain comfortable for long periods of time. Some headphones can feel too tight or too heavy, or put too much pressure on the ears or scalp, and few can be worn for hours on end without discomfort.

We also look at what the headphones include as part of the package. Many headphones come with detatchable cables and carrying cases, and earphones often include multiple sets of eartips so users can find the most comfortable fit. The accessories (and with them, functionality) you get for the price is an important factor when evaluating headphones.

Features and Connectivity Testing

Some headphones and earphones incorporate active noise cancellation (ANC), which employs a built-in microphone to measure outside noise and produce an opposing signal to counter that noise. If a pair of headphone have ANC, we determine how well the feature works and how much it disrupts the audio playing back. In addition, we also check if the headphones can be used passively and unpowered, or if they become unusable when the battery is dead.

Headphones can also function as headsets if they include a different microphone either in the earcup, on a boom extending from the earcup, or in a small module on the headphone cable. We evaluate how well the microphone picks up voices and, if the microphone has a noise-cancelling feature, how well it blocks out street noise from a call.

Typically, wired headphones use a 3.5mm connection. Most wireless headphones use Bluetooth. Some wireless headphones also have a wired option. We check all of these possibilities for each set of headphones we review. We also heavily factor in controls, especially for wireless models, checking for functionality and ease of use.

For Bluetooth headphones, we look at how easy it is to pair them with various mobile devices and how reliable the connection is. If they work with an app, we evaluate how much value it brings to the table. User-adjustable EQ is a big plus in our book.

And for true wireless earphones (where there is no cable connecting the two earpieces), we also consider the utility of the included charging case, including how big it is and how much extra battery life it holds.

Testing With Music

To evaluate audio quality, we play multiple tracks from multiple genres to determine weaknesses and strengths. Since headphones often heavily boost or sculpt deep bass, we test deep low-end reproduction with The Knife's "Silent Shout," a track with very deep bass synth and kick drum hits. The Roland TR-808-style bass kick in the song is a rite of passage through which all speakers and headphones must endure, and only the strong ones can reproduce it with a sense of power, and without crunchy, unpleasant distortion as we turn the volume up.

Besides the bass test, we cycle through multiple songs in the jazz, classical, rock, metal, and dance genres, to get a better idea of how each is handled. Every genre of music tends to have its own emphasized instruments and frequency ranges, like the low rumble of an upright bass on a Miles Davis recording, or the deep-but-crisp baritone vocals on a Bill Callahan track. Depending on a headphone's response across the entire audio spectrum (usually between 20Hz and 20kHz), a given model might make a synth-heavy dance track sound amazing, but classical and jazz music ends up muddled or even too bright, just to give one possible example. Similarly, even though a pair of headphones might capture the guitar riffs and screeching vocals of heavy metal well, they might lack enough low-end force or speed to faithfully reproduce bass-heavy funk songs.

Songs can vary heavily in balance based on how they were mixed, so we don't randomly shuffle through tracks, either. The songs we play are ones our reviewers have listened to hundreds of times across dozens of different speakers and headphones, including very high-end models, so we know exactly how they should sound, and exactly what is being reproduced well or poorly. At this point, every PCMag editor analyst has "Silent Shout" etched into their brain.

For more, our headphone buying guide can help you find the right model for your needs. Once you pick the perfect pair, check out our 5 easy tips to extend the life of your headphones.