All of us have unique ears. Calibrating a headphone for your own ears is like adjusting the lenses on your glasses to your eyes.

And just as with glasses, individually calibrated headphones make you hear clearer and crispier sound, allowing you to distinguish its minuscule details. You understand speech better and you pick up individual instruments more easily.

With Hefio headphones, calibrated playing needs only three quick steps.


The headphones play an audio signal in your ear and record it back with the built-in microphone


Our analysis algorithm estimates the individual frequency response at the eardrum


Enjoy audio calibrated for your ears, and adjust it with a target response of your choice

A Nordic startup built on achieving perfect sound quality

Hefio is a company created by professional acoustic developers in 2014. We are developing technology for self-calibrating headphones and other hearing devices for individually optimized sound. Through our technology each person is able to listen to music as it should sound in their ears. The technology is based on experience acquired through 30 years of research in hearing and audio signal processing.

Sound Quality

Our first and foremost goal is to achieve an unbeatable sound quality


We strive for design solutions that combine wearing comfort with excellent acoustics


Expertise founded on academic and industry experience