An Australian software program is fast becoming the new international standard for
prescribing hearing aids – the professional task of adjusting hearing aids to make sure they
are the best fit for each user.

Developed by the HEARing CRC and its Core Partner the National Acoustics Laboratories (the
research division of Australian Hearing), the NAL-NL2 program is set to become the
preferred way to fit hearing aids so that wearers have higher-quality hearing.

According to a 2005 World Health Organisation study, about 28 million people worldwide
wear hearing aids. For them to be effective, they need to be adjusted to match an
individual’s unique hearing loss so they are comfortable to wear, and provide the greatest
benefits to communication in different sound environments and situations.

Fitting a hearing aid to an individual’s hearing-loss pattern has traditionally involved
manually adjusting small knobs and switches to reduce or enhance particular frequencies
and sound levels.

With the arrival of computers, adjustment is conducted through a
computer interface, and the range of performance characteristics achievable with any single
hearing aid has increased markedly, making the task of adjustment more complex.

The international release of NAL NL2’s predecessor, NAL-NL1, in 1999 made it easy for
audiologists to apply a complex procedure that prescribed how the hearing aid should be
adjusted so that the hearing aid was most likely to provide optimal performance for each
individual.

Adjunct Prof. Harvey Dillon (NAL Director), who played an instrumental role in the
development of the NAL NL1 and NAL-NL2 prescription methods, said the success of NALNL1
lies in its ability to provide good speech intelligibility while still providing hearing aid
wearers with the overall loudness they prefer in different situations.

“NAL-NL2 is based on the same philosophy, but incorporates more extensive data on how
much information hearing-impaired people can extract from speech at different levels and in
different frequency ranges. It uses more sophisticated methods of predicting speech
intelligibility and loudness for people with different degrees and configurations of hearing
loss.

The final formula, which brings all the data together, is also more sophisticated and is
based on neural network mathematics,” Adjunct Prof. Dillon said.

NAL-NL2 has been licensed to all of the major international hearing aid and audiological test
equipment manufacturers, continuing the successful delivery of HEARing CRC technologies
internationally and making Australia the world leader in hearing-aid prescription software.

The Cooperative Research Centres (CRC) program is an Australian Government Initiative.
For further information contact: Greg Lawrence, HEARnet & Media Manager
e: glawrence@hearingcrc.org, mob: 0431 426 623.