Gadgets Technology

Aftershokz: Revolutionary headphones pass the sound over the bones

Written by Andy Prosper

The new headphones TrekzAir from Aftershokz are … let’s say different. It would be the fact that they send their sound directly over their bones – and that sounds like a booming skull.

It’s a strange feeling when I wear my TrekzAir new Bone Conducting Headphones for the first time. A bit as if suddenly a bionic implant sitting on my temple, which makes music develop directly in my brain. The sounds are clear, but at the same time, the ambient sounds are present. Not muted, like a headphone that does not shield properly, but just as loud as ever. So I can talk without switching off the music or listening to a car in the street – at least as long as it is not an electric car.

The special thing about this TrekzAir Bone Conducting headphones is that they are not worn in or over the ear, but are placed on the back cheek below the temple. The TrekzAir of Aftershokz tested by me was presented at the IFA 2017 and look similar to classic sportsline with straps. They transmit sounds through vibrations to the bone directly into the ear rather than as normally via the vibration in the air. Music feels extremely intense, but also language like a podcast or the integrated hands-free system is very well understood.

In medicine, this type of hearing is called bone conduction. It is used for special hearing aids in which the auditory canal, the eardrum and the auditory ossicles are easily skipped. Said device then direct the sound directly onto the olfactory, says Mark Praetorius, head of the Otologie at the Heidelberg University Hospital. In order to hear something about bone sound, then only “the hearing aid and the inner ear still work well”.

The TrekzAir headphones from Aftershokz are primarily intended for people with hearing impairments. Rather, they are to help me with jogging or cycling, so that I am contempt, music is not completely shielded from the outside world. And that works quite well – at least as long as I do not ride through the busy city center or the public transport. Then the ambient noise quickly drowns the music and I hear nothing more.

This is exactly where the biggest problem with the TrekzAir headphones is: If I turn the volume up, to overdrive even car and suburban noise, they begin to vibrate violently. It’s kind of like someone holding an electric toothbrush against the temple. The sound itself remains clear, even the bass does not exceed. But it is unpleasant.

40 to 50 decibels would be lost by the skin resistance in the bone sound, says ENT specialist Praetorius. This is impractical when it comes to street noise, but it also has an advantage: it can never be so loud that it can be damaged. Too much of the sound is simply shielded. “With such a headphone you have a certain degree of protection,” says Praetorius.

$150, Available for pre-order at

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Andy Prosper