1. Analyzing the ear

The personalization is achieved by first estimating the sound pressure frequency response at the eardrum evoked by the headphone. This response is used to determine the parameters needed to customize the sound for each user individually.

2. Personalizing

The parameters calculated in the analyzing stage are automatically implemented in the audio players of your smartphone, tablet, laptop or computer. As a result the frequency response at your eardrum is equalized to perfection.

3. Play

When played back through Hefio’s headphones and audio player the audio streamed through, e.g., Spotify, played from your device, or received from Internet radio will be customized to your ears.

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Hefio headphones sound great even without self-calibration and they work without any additional software. Personalization however requires Hefio software, which is free for Hefio headphone owners. The software suite operates in cross-platform manner: for example, personalization may be performed on Android and utilized in OSX PersonalEQ application. After reading the short introduction below, please head to respective application pages for usage and download instructions.
Hefio Calibrator
  • Personalization is carried out using a mobile application, which runs on iOS, Android and Windows Phone devices. The process is extremely easy to use – it requires just a press of a button – and takes less than a minute to complete. The app scans both ears with a short white noise segment, and sends the captured response to our proprietary server side algorithm for analysis.
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Hefio Player
  • In addition to Calibrator functionality, Hefio Player supports content streaming from Spotify, device media and online radio stations. These streams are processed with our EQ algorithm for optimal sound quality through the calibrated Hefio headphones. Two EQ target selections allow flat and natural audio enhancement profiles.
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Hefio Personal Equalizer
  • Hefio PersonalEQ runs on OSX and Windows platforms. It enhances the output of any application that sends its audio to the default audio output of the device. These include – but are not limited to – media players, audio and video streaming service clients, web browsers and games. The users may further configure PersonalEQ according to their taste: flat and natural audio enhancement profiles and an additional 31-band user EQ enable further customization. Premium users may even choose between biquad and convolution based EQ implementations.
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About us

We know how important the sound quality is

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 20 years of research in hearing and audio signal processing.

  • Expertise on Acoustics

    Four team members are PhDs in different fields of acoustics and sound


    Hefio headphones are throughtly designed to fit the shapes of ears. The design follows the shape of exterior of the ear as well as the ear canal. The appearance is an unique combination of in-ear and on-the-ear headphones utilising the best advantages of these both types. Compared to traditional in-ear headphones, Hefio headphones do not create an occlusion effect in the ear canal.


    The sound quality of our headphones have been intensively studied by our experts. Inherently, Hefio headphones have sufficiently flat frequency response. Frankly speaking, the sound quality is unbeatable.


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