Cambridge software improves quality of sound for hearing aid users

November 08, 2012

A new software product developed by researchers at the University of Cambridge could greatly improve sound perception for users of hearing aids.

The software prescribes the amount of amplification of high-frequency sounds required to restore the audibility of such sounds. This increases the frequency range of sound that individuals with hearing loss are able to detect, improving speech perception, sound localisation and the ability to hear certain musical sounds, when compared with current methods. Results of an evaluation of the software were published recently in the journal Ear and Hearing.

Approximately ten percent of the UK population has hearing loss great enough to cause them problems in everyday life. As hearing loss usually increases with age, the proportion of individuals with hearing loss will increase rapidly as the population ages in the coming decades.

The main treatment for hearing loss is hearing aids, which amplify and sound for the wearer in a frequency and level-dependent manner. In order for users to get the full benefits of a hearing aid, the device must be adjusted according to the wearer's pattern of hearing loss. The concept is similar to adjusting glasses for vision loss; however even a properly adjusted hearing aid will not completely restore hearing to normal.

Hearing loss typically occurs at high frequencies, and individuals with hearing loss can only hear comfortably within a small intensity range at those frequencies. While the threshold for detecting a certain sound may be higher for someone with hearing loss, the level at which sound is uncomfortably loud is often similar for individuals with hearing loss and those with normal hearing. To deal with this problem, hearing aids split sound into large numbers of frequency channels, or bands. Within each band, weak sounds are amplified while strong sounds are not. This is called multi-channel automatic gain control.

Researchers at the University of Cambridge have developed CAM2, a new method of fitting automatic gain control based on the audiogram of the user. An audiogram shows an individual's threshold for detecting sound at different frequencies.

"Until recently, hearing aids only provided amplification for frequencies up to four or five kHz, whereas a person with normal hearing can hear for frequencies up to 15 or 20 kHz," said Professor Brian Moore of the Department of Psychology, who led the development of CAM2. "Manufacturers have recently released hearing aids that can amplify frequencies up to 8 or 10 kHz, but existing fitting methods do not give any recommendations for those higher frequencies." The CAM2 method, however, extends the fitting range up to 10 kHz.

Higher frequencies help distinguish sounds such as "sh", "ch" and "f". In challenging listening situations, such as in a room where several people are speaking at once, the higher frequencies make it much easier to understand the person you want to listen to. The higher frequencies can also improve sound localisation, making it easier to identify where a particular sound is coming from.

A recent study compared the CAM2 method with NAL-NL2, which is a fitting method used by the NHS and many other health organisations worldwide. Judgments of overall sound quality were obtained for male and female speech in both quiet and noisy environments, and for four different types of music (classical, jazz, a man singing and percussion). Most participants in the study showed a preference for CAM2, both for overall sound quality and for the clarity of speech in a noisy situation. Further studies are planned over the coming months, in order to test more subjects with a wider range of hearing loss.
-end-
The CAM2 software is being commercialised by Cambridge Enterprise, the University's commercialisation group.

Cambridge Enterprise University of Cambridge

Related Hearing Loss Articles from Brightsurf:

Proof-of-concept for a new ultra-low-cost hearing aid for age-related hearing loss
A new ultra-affordable and accessible hearing aid made from open-source electronics could soon be available worldwide, according to a study published September 23, 2020 in the open-access journal PLOS ONE by Soham Sinha from the Georgia Institute of Technology, Georgia, US, and colleagues.

Ultra-low-cost hearing aid could address age-related hearing loss worldwide
Using a device that could be built with a dollar's worth of open-source parts and a 3D-printed case, researchers want to help the hundreds of millions of older people worldwide who can't afford existing hearing aids to address their age-related hearing loss.

Understanding the link between hearing loss and dementia
Scientists have developed a new theory as to how hearing loss may cause dementia and believe that tackling this sensory impairment early may help to prevent the disease.

Study uncovers hair cell loss as underlying cause of age-related hearing loss
In a study of human ear tissues, scientists have demonstrated that age-related hearing loss is mainly caused by damage to hair cells.

Hair cell loss causes age-related hearing loss
Age-related hearing loss has more to do with the death of hair cells than the cellular battery powering them wearing out, according to new research in JNeurosci.

How hearing loss in old age affects the brain
If your hearing deteriorates in old age, the risk of dementia and cognitive decline increases.

Examining associations between hearing loss, balance
About 3,800 adults 40 and older in South Korea participating in a national health survey were included in this analysis that examined associations between hearing loss and a test of their ability to retain balance.

Veterinarians: Dogs, too, can experience hearing loss
Just like humans, dogs are sometimes born with impaired hearing or experience hearing loss as a result of disease, inflammation, aging or exposure to noise.

Victorian child hearing-loss databank to go global
A unique databank that profiles children with hearing loss will help researchers globally understand why some children adapt and thrive, while others struggle.

Hearing loss, dementia risk in population of Taiwan
A population-based study using data from the National Health Insurance Research Database of Taiwan suggests hearing loss is associated with risk of dementia.

Read More: Hearing Loss News and Hearing Loss Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.