NEW TECHNOLOGIES FOR ADULTS WITH PRE-LINGUAL PROFOUND HEARING LOSS
Smith J.
Audiological Consultancy, South Yarra, Australia.
Individuals with profound hearing loss have traditionally been fitted with hearing aids which provide high gain and high power. The goal has been to provide maximum loudness on the assumption that they need volume to hear and understand speech. Without audibility there can be no intelligibility, but it is now appropriate to review our goals when fitting individuals with severe/profound hearing loss.
Available gain is not achievable gain if the hearing aid whistles. Multi-band active feedback cancellation systems offer an electronic solution to this problem so the desired gain can now be achieved, but high gain may not necessarily improve speech understanding. Further, hearing aids now include additional features, such as directional microphones and noise reduction, to assist the user when listening in noise. There has been little consideration of the benefits of these technologies for individuals with profound hearing loss.
A systematic approach will ensure hearing for conversational speech, but it is high gain for soft sounds that optimises the fitting for speech understanding. This gain is achieved through a low compression threshold, not through power. Similarly, if the loss is associated with a “dead region of the cochlea” the user cannot access high frequency speech cues, regardless of the power. To ensure access to these sounds, new generation hearing aids now apply frequency lowering technology.
This paper describes an case study for an adult with a pre-lingual severe/profound hearing loss, who transitioned from a super-power device to a lower powered device, the Widex Mind440 -19 +AE, which has the alternative feature set outlined above. It details the response of the client and the lessons learnt when determining how to meet the needs of this particular client group. The relevance of counselling strategies and in situ demonstrations will be discussed.
E-mail: jensmi@ozemail.com.au
