Hearing impairment is becoming increasingly prevalent in society, which is impacted by the growing number of elderly people in the population. Latest figures from the World Health Organisation estimate that around 5% of the population – or 430 million people – have a disabling hearing impairment (defined as a hearing loss of at least 40 dB in the better hearing ear) which could benefit from rehabilitation. This figure is projected to rise to 700 million people by 2050.
There are many different types and degrees of hearing impairment, and a recent infographic developed by the Aural Diversity project highlights the wide range of hearing dysfunctionthat people can experience. At a broad level, hearing impairment is classified medically by the location of impairment, as follows:
Conductive – impairments in the conductive path of the outer ear and middle ear
Sensorineural – impairments in the inner ear and auditory nerve
Central – impairments in the central auditory nervous system).
These impairments cause different types of hearing deficits, One of the most common effects of hearing disorders is a hearing threshold shift or a worsening of people’s ability to hear quiet sounds, including the subtle details of speech and music. Impairments can also cause distortions such as smearing which can increase difficulties understanding speech and appreciating music.