Radio aids – optimising listening opportunities: Guide

Glossary

ALD:  ‘Assistive Listening Device’ is used to describe personal devices which help overcome hearing loss.  These can be stand alone or used in conjunction with hearing devices such as hearing aids.

Assistive Listening Technology: You may also see Assistive Listening Device (ALD).  These are used to improve ability to hear in a variety of situations where it is difficult to distinguish speech in noise.  The three main technologies use induction loops, infrared and radio frequency (RF).  The latest ALDS are wireless and use the same 2.4GHz technology platform as is used with Bluetooth and Wi-Fi devices.

Attenuator:  This reduces the strength of an audio signal.  Used with a stetoclip when listening and checking powerful hearing aids so the listener’s hearing is not damaged.

Audible:  a sound which is able to be heard.

BAHA:  A bone anchored hearing device based on bone conduction.  It is suitable for CYP who have problems in the outer or middle ear or are unable to wear a behind the ear hearing aid.  Young children tend initially to wear it on a softband.  It can also be fixed to an implant in the skull which is inserted under surgery.

BATOD:  British Association of Teachers of the Deaf.  BATOD is the professional association for Teachers of the Deaf in the UK representing the interests of Teachers of the Deaf and other professionals working with deaf children and young people.

BATOD Foundation:  The BATOD Foundation is a research, training and information based charity dedicated to improving the life chances of deaf children and young people by disseminating the outcomes of research projects supported by the Foundation.

BKB sentence test:  Lists of 10 sentences, each containing 50 key words put together by Bamford Kowal and Bench for testing the ability of hearing-impaired children (usually >8 years old) to hear words in sentences.   The test is scored by asking the child to repeat the spoken sentence and identifying the correctly spoken target words.  The final score is the number of correctly identified words from the list of 50 expressed as a percentage.  The test can be administered in quiet conditions or in presence of background noise.

Cochlear Implant:  A Cochlear Implant provides a means of hearing for children and adults who otherwise receive no or limited benefit from conventional hearing aids.  It is an electronic medical device which replaces the function of the damaged inner ear (cochlea).  It consists of an internal receiver/electrode package which is surgically implanted under the skin, and an external speech processor worn behind the ear or on the body.

CYP:  Children and young people  (in context - child or young person)

dB:  A decibel is a measurement which indicates how loud a sound is.  The  healthy human ear can hear approximately between 0dB and about 140dB.  The smallest audible sound is about 0dB – silence, but a sound which is 1,000 times more powerful than silence is measured at 30dB.  Normal conversation is measured at about 60dB.

DCSF:  Department for Children, Schools and Families, a government department in England between 2007 and 2010 which was replaced by the DfE in 2010.

Direct Input shoe: This allows direct connection of a hearing aid to other audio equipment.  Often called a shoe or boot.  They are specific to the make and model of each hearing aid.  

Educational Audiologist:  A qualified Teacher of the Deaf who also has an additional qualification in audiology working in an education support service or school for the deaf.

ETSI:  The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardisation organisation in the telecommunications industry.

FM:  Frequency modulation  A FM radio aid system works wirelessly on a similar basis to VHF radio.  It uses higher frequency bands than broadcast radio and does not require a license.  

FM ChIP:  The FM ChIP was originally developed to assess young cochlear implanted children’s readiness to have a radio aid fitted.

FM Working Group:  Now called the UK Children’s Radio Aid Working Group.  This was set up to encourage developments in the field of personal radio aids, promote good working practice and to share information.

Hearing:  Hearing, in humans, is the ability to detect and perceive sound using ears, which is then transmitted to the brain.

Hearing loss (temporary/permanent) also known as hearing impairment, is a partial or total inability to hear.  A deaf person has little to no hearing. Hearing loss may occur in one or both ears.  A temporary hearing loss, usually a conductive hearing loss, is caused by a problem in the ear canal, the eardrum or in the middle ear which prevents sound being effectively carried into the inner ear.  Some CYP may have more permanent conductive hearing losses which may fluctuate in hearing levels because of persistent infections.  A sensorineural hearing loss is a permanent hearing loss.  This is usually caused by damage to the hair cells in the cochlea or to the neural pathways of hearing.  

Inverse Square Law:  In this MESHGuide, this applies to the reduction in the volume of sound when the distance from the source is increased.  The sound intensity is reduced in an inverse proportion to the square of the change in distance.  For example: if the distance is doubled 22 = 4, the inverse of 4 is ¼ therefore the signal is one quarter of the original volume when it reaches the listener’s ear.

Intelligibility:  In the context of speech, intelligibility refers to the amount of the speaker’s output which can be understood.  This will be affected by background noise.

Listening:  Listening requires effort from the listener and is a conscious processing of sound.  It involves complex affective, behavioural and cognitive processes.

LA:  Local Authority is responsible for providing amongst other services, education, in a particular area of the UK.

Latency:  The time taken for a piece of electronic equipment to respond to commands or changes in conditions.  This can affect the user’s enjoyment.

MCHAS:  Modernising Children’s Hearing Aid Services.  Good Practice Guidelines.

NDCS:  The National Deaf Children's Society: a charity dedicated to creating a world without barriers for deaf children and young people

Parrot and Parrot plus:  Portable automated speech tests using digitally and balanced male and female human voices.

Personal radio aid:  A device comprising a transmitter, which the speaker wears, and receivers which the child or young person wears.  These make speech more audible in difficult listening conditions, such as background noise, reverberation and distance.

Quality Assurance:  The checks used to ensure that a product or service meets the specified requirements.

Receiver:  The part of the personal radio aid worn by the CYP.  It can be body worn, attached to hearing technology by wires; ear level, attached directly to the hearing technology; integrated, part of the hearing technology itself or  using a personal neckloop.

Reverberation:  The persistence of a sound after its source has stopped which is caused by bouncing of sound waves off hard surfaces before reaching the listener’s ear

SEN:   Special Educational Needs. The SEN Code of Practice suggests four main areas of special need; Cognition and Learning; behaviour, emotional and social development; communication and interaction; sensory and/or physical needs.

SEND:  Special Educational Needs and Disabilities

Soundfield system:  An amplification system that evenly distributes the teacher’s voice around the room, using a microphone and speakers thus enabling pupils to hear equally well regardless of where they are seated or which direction the teacher is facing.

Speech in Noise Tests:  Evaluation of personal radio aids and hearing aid technology is important.  Speech testing in quiet and babble noise is used quite routinely.  There are a range of tests available for different age groups, each with its own standardised systematic approach.  

Speech intelligibility:  In speech communication, intelligibility is a measure of how comprehensive and understandable speech is in given conditions.  Intelligibility is affected by the quality of the speech signal, the type and level of background noise, reverberation and the properties of the communication system used.

SIN or Speech in Noise tests:  Speech is presented in quiet and with varying levels of background noise to ascertain the difficulty the child has in understanding the speech in the presence of noise.  Sentences or single words can be used.

Stetoclip:  A device which can be used by a hearing person to listen to a hearing aid to make sure it is working, see also attenuator.

Test Box:  This is a sound treated enclosure which gives accurate repeatable measurements of a hearing aid and its functioning.  It is also used by Teachers of the Deaf and Educational Audiologists to monitor the function of hearing aids and  to ensure that when a radio aid is fitted, it is balanced with the hearing aids, so the sound level received gives the desired advantage and the CYP has a good listening experience.

T programme: The T programme or setting on a hearing device works by activating a telecoil in the aid which works with induction loop systems to bring sound directly to the hearing aid via magnetic fields.  Cinemas, theatres, banks, shops etc may have loopstems installed, which a listener can access by switching to the T programme.

ToD /ToDs:  A Teacher of the Deaf is a qualified teacher who has an additional mandatory qualification in teaching deaf children.

Transmitter:  This is the part of a personal radio aid system which is worn or held by the person talking, it can also be plugged into a TV/audio source.

The UK Children's Radio Aid Working Group -  Formerly the FM Working Group  This was set up to encourage developments in the field of personal radio aids, promote good working practice and share information.