Identifying and Measuring Factors Limiting Binaural Auditory Processing in Normal Hearing Listeners and Listeners Having Slight Hearing Loss
Abstract
For the past several years, a burgeoning area of interest within the auditory community has been the investigation of so-called ???hidden hearing loss.??? Anatomical and physiological studies have shown that important peripheral auditory neural coding deficits may occur even in the absence of measurable losses in absolute hearing sensitivity. Such findings suggest that, for humans, important processing deficits may exist while being transparent to the type of audiometric measures commonly used in the clinic. Our research, conducted under the auspices of Award No. N00014-15-1-2140 has revealed that even very small elevations in audiometrically normal thresholds at high frequencies can be associated with measurable and substantial deficits in binaural processing.One goal of our proposed program of research includes identification of deficits of fundamental auditory abilities that can reduce operational performance in both civilian and military settings. A second goal is to develop ways of identifying individuals who are likely at risk before substantial and/or irreversible damage occurs. A third goal is to identify, in a mechanistic sense, the nature and type of deficit so that proper and effective forms of remediation can be implemented.Specifically, we seek to assess whether and to what degree the deficits in binaural detection we discovered in listeners with ???slight??? and/or ???hidden??? hearing loss lead to or are associated with deficits in more complex listening situations. In order to fulfill those objectives, experiments are proposed with three areas. The first area concerns specification and further characterization of the types of ???internal??? neural processing noise that underlie the binaural deficits we discovered in listeners having clinically (i.e., audiometrically) defined ???slight??? hearing loss. Such information is vital for a proper understanding of why some people may complain about hearing difficulties in complex acoustic environments only to be told that they have clinically normal hearing. The second area concerns ???binaural interference,??? a well-studied degradation in binaural processing that occurs when a source of sound in one frequency region is accompanied by a second, simultaneous sound that occupies a frequency region that is well removed from that of the first sound. We will test the reasonable hypothesis that binaural interference is exacerbated in listeners having slight hearing loss. Such difficulties may be manifested by deficits in people???s abilities to localize external sources of sound and/or to lateralize, intracranially, the perceptual locus of sources of sounds presented via earphones.The third area addresses how neural processing deficits of the sorts described above might limit or compromise binaural speech perception in noisy environments. We propose to measure both binaural release from masking and binaural speech intelligibility with listeners characterized as having audiometrically normal hearing and with listeners having, at worst, slight hearing loss. All three areas of research have value for military application because they will provide information necessary for identifying, understanding, and resolving auditory limitations or deficits that can degrade operational performance.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 26, 2018
- Source ID
- N000141812437
Entities
People
- Leslie Bernstein
Organizations
- Office of Naval Research
- United States Navy
- University of Connecticut