Musical Vibrations

by Professor Carl Hopkins

originally published in the Institute of Acoustics blog at

Eleven million people in the UK have some form of hearing loss (approximately one in six people), and there are more than 900,000 people with a severe or profound hearing loss. Whilst communication tends to receive the most attention in research, access to music, and participation in music-making can be important too. To quote Dame Evelyn Glennie, “People think that music means nothing to the deaf; but it is important to them whether they are interested in it or not. The satisfaction of feeling vibrations, and being able to communicate through music, gives deaf children the greatest pleasure.”.

To support d/Deaf people in music performance, education, appreciation and production, the Musical Vibrations project is being run by Prof. Carl Hopkins, Natalie Barker (music teacher) and Dr Gary Seiffert from the Acoustics Research Unit at the University of Liverpool. This project aims to demonstrate the potential of using vibrotactile feedback (i.e. sound presented as vibration that is felt via the skin).

To demonstrate its potential in music appreciation, we invited WJ, who became profoundly-deaf about 8 years ago, to come and ‘feel’ one of her favourite songs from the past. Her wonderful reactions can be seen in this video:

The initial research considered the feasibility of group rehearsal, performance and improvisation for musicians with hearing impairments. The basic concept being that any musical performance can effectively be turned into a computer-controlled amplified performance where the sound from each instrument is taken to a mixing desk and sent back as a vibration signal to be presented to the body of the musician. This established that the concept was feasible for the perception of notes from C1 up to G5 with safe levels of vibration presented to the glabrous skin of the hands and/or feet.

The equipment is currently installed in Derby Royal School for the Deaf where it is being used to deliver music lessons. The teacher has commented that “It is changing the way I teach” and on entering the room the children now immediately take their shoes and socks off before the lesson has even started.


Carl is a Professor in Acoustics and Head of the Acoustics Research Unit at the University of Liverpool. He is a Fellow of the Institute of Acoustics and a Chartered Engineer. Carl was awarded the Tyndall Medal in 2012 for his achievements and services in the field of acoustics, and awarded the Engineering Medal in 2016 in recognition of his outstanding contribution in the field of acoustical engineering. 

His research primarily focuses on the measurement and prediction of sound and structure-borne sound in the built environment with applications to building, automotive, aeronautic, or marine structures. He has published a sole-author monograph on sound transmission in buildings that is referenced in British, European and International Standards. Recent research on using vibrotactile stimuli to facilitate interactive performance between musicians with hearing impairments was shortlisted for the 2013 THE award ‘Research project of the year’.

3.7.19 Origins…

Many creative ideas begin in places where we least expect them. Musical Vibrations came about during a car journey.

Professor Carl Hopkins, head of the Acoustics Research Unit (ARU) at the University of Liverpool, first dreamt up the idea that would result in the Musical Vibrations project when a radio broadcast in his car connected his research into floor vibration with the phenomenon of music being perceived as vibrations through the floor of a concert hall as described by Dame Evelyn Glennie.

His initial thoughts were of designing performance decks around each instrument to maximise vibrational feedback and remove potential variations between different concert performance spaces.

So, research began in 2012, in conjunction with the Royal Northern College of Music, to explore how vibrotactile technology could support musicians with a hearing impairment. The intention was to open up new opportunities for people to become musicians and perform with other musicians. Publications on this research can be found here. This research was funded by the Arts and Humanities Research Council (Grant No. AH/H008926/1) video above summarises the concept outlined in the research, which was that it was possible for musicians to perform together successfully using vibrotactile feedback alone, i.e. without being able to see or hear each other. The video promoted the research findings to a much wider audience and had more than 1000 views in its first week online. To date, it has been viewed over 6,000 times.

“The worst loudspeakers in the World”

We’re proud to possess some of the worst loudspeakers in existence at the University of Liverpool. Originally designed to make walls and aircraft parts shake during testing, they are incredibly inefficient. So much so that you can hardly hear them at all. They’re so bad we call them ‘shakers’. 

Four Vibrotactile foot shakers
Foot shakers

But when you touch them it’s a different story; if you connected one to an electronic piano you would be able to feel the difference between musical pitches all the way from C1, the very bottom of a piano, up to G5, which is around where an average female voice tops out.

It’s a more efficient way of doing what deaf people have been doing since the invention of amplified sound; touching surfaces in rooms where loud music is being played to ‘hear’ music through the skin.

The shakers can be used on the hands, heels and forefeet so that up to six, each connected to a different musical instrument if desired, can be used at once.

Deaf musicians can feel the vibrations from the playing of other musicians through their feet whilst keeping hands free for playing along with the ensemble without relying on visual cues. Our Day Tripper video illustrates the concept.

The aim of the Musical Vibrations project is to bring the shakers into schools, music venues and recording studios where they can create a real-life impact. We took the shakers to the Royal School for the Deaf, Derby earlier this year, and worked with around 40 children from key stages 1 to 4.

The next phase of our research, to find out exactly what the shakers bring to music education, starts in 2019. This involves teachers and pupils using the shakers in music lessons over a period of four weeks.

We’re currently looking for more music schools and resource bases to take part.

How can Limping Chicken readers help?

  • If your child attends a school for Deaf children or a resource base at a mainstream secondary, please mention this project to the school. More information can be found on our website
  • If you’re a music teacher, TOD, or Head teacher, drop us a line at
  • Follow us on Twitter @MUSVIB  to help us get the message out!

If results are positive, and the positive response we have had so far is very encouraging, then our plan is to seek charitable funding to enable systems to be purchased for all schools and deaf resource bases.