Over-ear, on-ear, in-ear or open-ear: which type of headphones should you choose?

Four ways to couple a speaker to the ear

All headphones place a small speaker, the driver, close to the eardrum. What changes from one form factor to the next is the volume of air trapped between the two, and how well it is sealed. The smaller and more closed that volume, the easier it is to produce powerful bass and block out noise; the larger and more open it is, the more natural and spacious the sound seems.

Over-ear headphones

Their ear pads completely surround the outer ear and rest against the head, not on the ear. The pressure is spread over a large area: this is the form factor you can wear the longest. The roomy ear cups hold 40 to 50 mm drivers, which reach deep into the bass without effort, and leave space for the mics and the battery that effective noise canceling requires.

It is also the only form factor that comes in an open-back version, prized for hi-fi and mixing. Its limits are practical: it gets warm in summer, travels poorly without a case and isn't suited to sports.

Best for: travel, remote work, gaming, studio work, listening at home.

On-ear headphones

Smaller, they set their ear pads directly on the outer ear. They gain in lightness and compactness, and often fold flat. In exchange, the cartilage of the ear bears the full clamping force: past an hour or two, many people feel discomfort, especially with glasses, whose temples end up pinched.

The seal against the outer ear is imperfect, which limits isolation and makes the bass sensitive to placement. The form factor is still a good compromise for short listening sessions, for kids (small heads, featherweight design) and for office headsets, where lightness comes first.

Best for: short commutes, kids, office calls.

In-ear earbuds

A soft tip seals the ear canal and places the driver a few millimeters from the eardrum. The volume of air to be moved is tiny: a 6 to 10 mm driver is enough for deep bass, provided the canal is perfectly sealed.

So all the performance rests on the ear tip. Too small, and it lets the bass leak out and the noise in; too large, and it hurts and eventually works its way out. Your two ears aren't always the same size. Memory foam tips conform to the canal better and isolate more than silicone, but they wear out in a few months.

There are also classic open-fit earbuds, which sit at the entrance of the canal without sealing it: they are comfortable and don't isolate, but they deliver little bass.

Best for: commuting, workouts, sleep, musicians on stage.

Open-ear: bone conduction and open earbuds

Here, nothing goes into the ear canal. Bone conduction vibrates the cheekbone, which carries the sound straight to the inner ear. Open earbuds, a more recent arrival, are small speakers suspended in front of the canal by a hook or a clip.

Either way, you hear traffic, announcements and conversations as if you were wearing nothing. That's a safety advantage for running or walking in the city. The price to pay is acoustic: with no enclosed volume, the bass is weak, and in a noisy environment the music is quickly drowned out. See the guide to bone conduction headphones.

Best for: running, walking in the city, shared offices, people who can't stand ear tips.

Comfort comes down to three things

• Weight. Under 250 g (about 9 oz), you forget you're wearing headphones. Over 350 g, your neck and the top of your head feel it after an hour, unless the headband is very well padded.
• Clamping force. Too weak, and the headphones slide around and the bass leaks out; too strong, and they cause headaches. A metal headband loosens slightly over time.
• Ear pad material. Faux leather isolates better but gets warm; velour and fabric breathe, at the cost of a little isolation. Replaceable ear pads double the lifespan of a pair of headphones.

Sources and references

1. IEC 60268-7 — Sound system equipment: headphones and earphones
2. ITU-T H.870 — Guidelines for safe listening devices/systems (WHO-ITU standard)