Cambridge software improves quality of sound for hearing aid users
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.
Provided by Cambridge Enteprise University of Cambridge
- Sound, vision & hearing loss Jun 24, 2011 | not rated yet | 0
- Novel genetic loci identified for high-frequency hearing loss Apr 26, 2012 | not rated yet | 0
- Our Health: Louder and louder world harms our hearing Feb 27, 2009 | not rated yet | 0
- A hearing aid you install yourself May 17, 2011 | not rated yet | 0
- Study finds not all hearing aids are created equal Aug 13, 2008 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
High blood glucose is associated with poor outcomes in hospitalized patients, and use of intensive insulin therapy (IIT) to control hyperglycemia is a common practice in hospitals. But the recent evidence does not show a ...
Other May 24, 2013 | 4 / 5 (1) | 0
Two out of five medical students have an unconscious bias against obese people, according to a new study by researchers at Wake Forest Baptist Medical Center. The study is published online ahead of print in the Journal of ...
Other May 23, 2013 | not rated yet | 0
Nanyang Technological University's (NTU) new medical school will be pioneering the use of plastinated bodies for medical education in Singapore.
Other May 23, 2013 | not rated yet | 0
A 2012 survey of internal medicine residents at Massachusetts General Hospital (MGH) – one of the nation's leading teaching hospitals – found that more than half rated the training they had received in addiction and other ...
Other May 22, 2013 | 5 / 5 (1) | 0
Early use of tracheostomy for mechanically ventilated patients not associated with improved survival
For critically ill patients receiving mechanical ventilation, early tracheostomy (within the first 4 days after admission) was not associated with an improvement in the risk of death within 30 days compared to patients who ...
Other May 21, 2013 | not rated yet | 0
(HealthDay)—Animals make great companions for senior citizens, but elderly people who always drive with a pet in the car are far more likely to crash than those who never drive with a pet, researchers have ...
58 minutes ago | not rated yet | 0
Coenzyme Q10 decreases all cause mortality by half, according to the results of a multicentre randomised double blind trial presented today at Heart Failure 2013 congress. It is the first drug to improve heart failure mortality ...
9 hours ago | 5 / 5 (2) | 5
Heart failure accelerates the aging process and brings on early andropausal syndrome (AS), according to research presented today at the Heart Failure Congress 2013. AS, also referred to as male 'menopause', was four times ...
8 hours ago | not rated yet | 1
Mortality and length of stay are highest in heart failure patients admitted in January, on Friday, and overnight, according to research presented today at the Heart Failure Congress 2013. The analysis of nearly 1 million ...
8 hours ago | not rated yet | 0
(AP)—Department of Justice lawyers have again asked a federal appeals court in New York to delay lifting age restrictions and prescription requirements on an emergency contraceptive popularly known as the morning-after ...
8 hours ago | not rated yet | 0