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Aside from helping you hear what the person next to you is saying, your ears reveal all sorts of clues about your environment - from the distance of objects to even the size of people around you.

And now researchers are looking into how these sounds can be manipulated to affect a person's mood and perception.

In one experiment in particular, experts proved that sounds can trick the brain into thinking they're touching a variety of different surfaces. 

Scroll down to watch the video and try the experiment yourself

During the test, a participant was asked to run her finger across a strip of smooth plastic (pictured). As she moved her hand, headphones played the sound of a finger moving across different surfaces.  Experts believe that auditory changes confuse and disrupt the brain, and this creates a mismatch between the senses

During the test, reported in New Scientist, a participant was asked to run her finger across a strip of smooth plastic.

As she moved her hand, headphones played the sound of a finger moving across paper, sandpaper and velvet.

The participant reported noticeable changes in how the plastic felt beneath her finger after each sound.

This test was devised by Dr Ana Tajadura-Jimenez for her Hearing Body project at University College London.

As part of the project, Dr Tajadura-Jimenez studies how auditory information generated by the human body affects how that person comes across, and how people see them.

'This mental representation we have of our bodies is essential for successful interaction with the environment,' explained Dr Tajadura-Jimenez.

'The representation is not fixed, but is continuously updated in response to the available sensory information.'

Previous studies have highlighted the role that sight, touch and a person's own perception - known as proprioception - play in representation.

But, the effect sounds have on these senses and experiences haven't been investigated in depth.

'Interestingly, the sounds that accompany almost every bodily movement are highly rich in information about the body and the space immediately surrounding it,' continued Dr Tajadura-Jimenez.

She used the example that the sounds produced when tapping on a surface tells people about the length and strength of their arm.

Dr Tajadura-Jiménez believes that auditory changes confuse and disrupt the brain, and creates a mismatch between the senses.

This is similar to the experience people have when viewing optical illusions.

When the sound of a finger moving across sandpaper (stock image left) and velvet (right) were played, the participant reported noticeable changes in how the plastic felt beneath her finger. Researchers want to study how sounds can be manipulated to affect a person's mood and perception

In the case of optical Illusions, colour, light and patterns are used to create images that deceive or mislead the brain.

The information collected by the eye is processed by the brain.

In the process of converting what it sees, the brain tries to make sense of the different colours and patterns. This creates a perception that doesn't match the image, and confuses the brain.

Similarly, in terms of audio changes, the information collected by the ear is processed by the brain, which then tries to make sense of the differences.

As the brain tries to account for discrepancies, it produces a variety of sensations. 

The sensations are similar to those experience when people watch optical illusions (pictured). In the case of optical Illusions, colour, light and patterns are used to create images that deceive or mislead the brain. The information collected by the senses processed by the brain, which then tries to make sense of it 

In another experiment, the pitch created by a person's footsteps was made higher or lower. When lower, the footsteps produced a sound that suggested the person was heavier than they were. This caused participants to report that their legs felt heavier and the steps felt laboured. Higher pitches made people feel lighter

The finger test is just one of a series of psychological experiments being carried out at University College London that explore how altering self-produced sounds in real-time changes perceptions.

This includes how space around the body is represented, actions that the body is capable of performing, and moods.

In another experiment, the pitch created by a person's footsteps was made higher or lower.

When lower, the footsteps produced a sound that suggested the person was heavier than they were. This caused participants to report that their legs felt heavier and the steps felt laboured.

By comparison, higher pitches made people feel lighter and thinner.