The branch of physics concerned with the properties of sound and vibration.

Assistive technology

An umbrella term that includes assistive, adaptive and rehabilitative devices for people with sensory differences or disabilities.


Term used to describe people who describe themselves as either Deaf or deaf :


Denotes people who are sign language users. People who identify as members of a cultural and linguistic minority whose first or preferred language is British Sign Language (USA: American Sign Language). The capitalisation is significant and is communicated as ‘big D Deaf’ in speech and sign. Members of the Deaf community do not view deafness as a disability.


Denotes people who have severe to profound hearing loss but who have English as their first language and may lipread and/or use hearing aids. A person who is deaf may also identify themselves as Deaf.


The number of times a complete cycle of vibration takes place, per second, is called the frequency of a sound and is measured in Hertz (Hz). We interpret frequency as the pitch of a sound. A higher frequency means a higher pitch.


Areas of skin which are free from hair e.g. palms of hands and soles of feet

Hand Arm Vibration Syndrome (HAVS)

HAVS is the medical term for symptoms caused by vibration damage that may occur in the fingers, hands and arms when working with vibrating tools or machinery. Vibration injuries are divided into three subgroups: neurological disorders, vascular and musculoskeletal.


Relating to the sense of touch, in particular relating to the perception and manipulation of objects using the senses of touch and proprioception.

Hard-of-Hearing / HoH

Describes a person who has some level of hearing loss. A hard of hearing person may have had a hearing loss since childhood, or have acquired it later on in life. The majority of hard-of-hearing people communicate using speech, possibly with a hearing aid and lipreading.

Hearing Impaired

This term is a technically accurate description of someone who is hard of hearing or who has no hearing. It is often used in clinical settings … however, many Deaf and hard-of-hearing people prefer not to be called impaired.


In music, the pitch of a note means how high or low a note is. The pitch of a sound is related to its frequency; we experience higher frequencies as higher pitches. The frequency of a note can be measured in Hertz (Hz). A note that is vibrating at 256 Hz will be caused by sound waves that vibrate at 256 times a second. This will be Middle C on the piano.


Relating to blood vessels. For example, the vascular system in the body includes all of the veins and arteries.


The perception of vibration through touch. It can be used either as a substitute for other senses (e.g. hearing, vision) or to enhance the information content.


A body is said to vibrate when it describes an oscillating motion about an equilibrium point. Vibration can be desirable: for example, the motion of a tuning fork, a mobile phone, or the cone of a loudspeaker. In many cases, however, vibration is undesirable, wasting energy and creating unwanted sound. For example, the vibrational motions of engines are usually unwanted.

Whole body Vibration (WBV)

WBV is experienced when sitting, standing or lying on a vibrating surface.