How headphones can sound 3D

Chad Underwood
3 min readAug 9, 2022

Spatial audio is surround sound for headphones.

A major benefit of watching a movie at a theater is the sound. You’re able to be immersed in the movie because the sounds are accurate. The theater gives you sounds from above, in front and to the sides.

This same surround sound tech is available on headphones.

Photo by Marius GIRE on Unsplash

Spatial audio has been available to the masses for a couple years.

You don’t hear much about spatial audio but it’s the future of music and movies. It took off with VR (virtual reality). More people are using headphones to watch and listen to content.

How you hear sounds

Your brains processes the sounds you hear.

The sounds around you go around your ear and into your ear hole. The sound travels around your ear depending on how low or high pitched they are. If the sound is behind you, your shoulders and head make the sound lower in volume to let your brain know the sound is behind you.

Then your brain processes how loud a sound is and the pitch to let you know where the sound is coming from.

How Spatial Audio works

Spatial Audio is mixed (processed by a sound engineer in the studio) the same way as surround sound.

The sound is separated by left and right. The sounds are delayed depending on where it’s supposed to be located. Then the volume for the sound is raised or lowered depending on the intended location.

This process is called HRTF (Head Related Transfer Function).

The difference is between a surround sound system and headphones is what happens when the sound is played through them.

Why headphone couldn’t have surround sound before

In the past, it wasn’t possible to get surround sound with headphones.

With headphones there’s typically 1 driver (speaker) per ear. Since both ears are concealed there’s no way for sounds to come from different directions. Because the sound goes straight into your ears.

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Chad Underwood

American writer sharing experiences in life, writing, technology, and content creation.