Investigation of low-sound-level auditory processing deficits
Research type
Research Study
Full title
Investigation of low-sound-level auditory processing deficits in humans after chronic exposure to very high noise levels.
IRAS ID
184199
Contact name
Lynne Macrae
Contact email
Sponsor organisation
Faculty Research Practice Co-ordinator
Duration of Study in the UK
3 years, 1 months, 30 days
Research summary
Research Summary
Exposure to very high sound levels have long been known to damage the mammalian hearing system. Until recently this damage has generally only been demonstrable as a loss of sensitivity to quiet sounds. Recent experiments using noise-exposed humans have shown subtle degradations that are largely independent of the loss of sensitivity. When the patient seeks treatment, remediation is primarily via a hearing aid. Although the hearing aid can restore audibility of weak sounds, the previously subtle losses will distort the perceived signal as it passes from ear to brain. The patient struggles to make sense of this distorted signal and the hearing aid therefore appears to be less effective than might be expected. We wish to measure performance in a variety of hearing tasks by participants who are first-time candidates for clinically-fitted hearing aids. The tasks fall into several categories:
(1) clinical measures of basic hearing function including, but not limited to audiometry,
(2) psychophysical tasks using specialist signals generated by the experimenter
(3) measures of speech intelligibility resulting from use of such hearing devices, or computer simulations of these devices.Participants will be grouped to have had either a history of high-, or a history of low-, noise exposure. Delivery of test stimuli will be via one of insert earphones, headphones or loudspeakers.
Summary of Results
Two studies were reported in peer-reviewed literature.
(a) extending a hearing test commonly used in audiology clinics so as to detect early signs of a new form of hearing damage was not successful. However, it did show further evidence that the classically-defined range of what is considered "normal" ie undegraded, hearing is too wide. Any loss of hearing sensitivity causes measurable loss of the proficiency of the hearing system when operating in a background noise.
(b) two possible separate tests of hearing proficiency failed to repeat previous evidence of this new form of hearing damage. Additionally, musicianship, independent of any hearing loss enabled better performance than that from non-musicians. This rendered one of the tests unreliable for use in future clinical use.Summary of Results
Two studies were reported in peer-reviewed literature.
(a) extending a hearing test commonly used in audiology clinics so as to detect early signs of a new form of hearing damage was not successful. However, it did show further evidence that the classically-defined range of what is considered "normal" ie undegraded, hearing is too wide. Any loss of hearing sensitivity causes measurable loss of the proficiency of the hearing system when operating in a background noise.
(b) two possible separate tests of hearing proficiency failed to repeat previous evidence of this new form of hearing damage. Additionally, musicianship, independent of any hearing loss enabled better performance than that from non-musicians. This rendered one of the tests unreliable for use in future clinical use.REC name
North West - Greater Manchester Central Research Ethics Committee
REC reference
16/NW/0260
Date of REC Opinion
20 Apr 2016
REC opinion
Favourable Opinion