Why Does Your Recorded Voice Sound Different?

Subject: Science & Technology | Tag: Established

You play back a recording of yourself, and the voice that comes out doesn’t sound like you. “That isn’t me,” you think.

Same voice, same mouth. So why does it sound like someone else? This article follows one explanation, not every one.

Your voice reaches you by two routes

When you speak, your voice reaches your ears through the air. That is how it reaches anyone standing near you. But it also takes a second route. It travels as vibration through your skull and jaw, straight to the inner ear. This is called bone conduction (sound carried to the inner ear through bone instead of air).

A listener across the room mainly gets the air route. You get both. In a 2008 article for AudiologyOnline, Ted Venema explains the difference. We hear ourselves through bone and air conduction together. Other people hear us through air conduction.

A microphone behaves like that listener. It picks up sound from the air. So a recording keeps the air route and leaves out the one that runs through your skull.

The skull route is not the only factor. The microphone, the room and the speakers all change the sound before it reaches you again. So bone conduction is part of the answer, not all of it.

The usual “lower to you” explanation rests on an assumption

The usual explanation is simple. The skull route emphasises low sounds, so you hear your own voice as lower than others do. Pavo Orepic and colleagues, writing in Royal Society Open Science in 2023, describe that skull effect as an assumption. They add that exactly how the skull and head tissues carry sound has not yet been formally defined.

Does the skull route help you recognise your own voice?

The same team tested this. Eighty-four volunteers took part, across three small studies. They heard short clips and judged whether each one sounded more like themselves or like someone else. Some clips had vibration added through the bone. With it, the volunteers found it easier to pick out their own voice.

The authors read this as evidence that bone-conducted vibration contributes to how we identify our own voice. But each clip was only half a second of a single vowel. The studies say little about everyday speech.

A recording is nearer to what others hear

I draw one conclusion from these two sources. It is my inference, not something either measured. A listener mainly gets the air route. So the playback you dislike is likely nearer to what others hear than the voice you are used to.

It is not identical. The microphone, the room and the speakers still shape it, and so does where the listener stands.

The short version: a recording leaves out the route that runs through your skull, which may be one reason it sounds unfamiliar.

Glossary

Air conduction. Sound that reaches your inner ear through the air, the ear canal and the eardrum.

Bone conduction. Sound that reaches your inner ear as vibration through the bones of your skull, without travelling through the air.

Sources

• Orepic, P., Kannape, O. A., Faivre, N., & Blanke, O. (15 February 2023). Bone conduction facilitates self-other voice discrimination. Royal Society Open Science, 10(2). Open access.
• Venema, T. (25 August 2008). Common Clinical Encounters; But Do We Really Know Them?