Adam Walker, Audiological Scientist, Manchester, UK

What is a hearing aid?

A hearing aid is a device that amplifies sound according to the patients hearing levels to provide access to the frequencies at which the patient does not hear as well as they should.Hearing aids should be programmed using “Real Ear Measurements” to ensure accuracy of fitting and optimal sound quality.  A correctly programmed hearing aid will usually apply more gain (volume) to quiet sounds than to loud sounds, this is called compression, and aims to ‘normalise’ loudness growth whilst avoiding discomfort caused by loud sounds being ‘too loud’.  Hearing aids come in a wide range of sizes, styles, colours and technology levels, based on the patients needs and hearing levels.

What is an assistive listening device (ALD)?

An ALD is a device that aims to improve the ‘signal-to-noise ratio’ between the sound source and the listener.  This is achieved by ‘streaming’ the sound source directly to the hearing aids, whether this be the TV, telephone, music or teacher / lecturers voice.  There are a wide range of ALDs that can be employed in different listening environments from the home to the classroom. hearing aids and