Auditory brainstem response latency in forward masking, a marker of sensory deficits in listeners with normal hearing thresholds.
In rodent models, acoustic exposure too modest to elevate hearing thresholds can nonetheless cause auditory nerve fiber deafferentation, interfering with the coding of supra-threshold sound. Low-spontaneous rate nerve fibers, important for encoding acoustic information at supra-threshold levels and in noise, are more susceptible to degeneration than high-spontaneous rate fibers. The change in auditory brainstem response (ABR) wave-V latency with noise level has been shown to be associated with auditory nerve deafferentation. Here, we measured ABR in a forward masking paradigm and evaluated wave-V latency changes with increasing masker-to-probe intervals. In the same listeners, behavioral forward masking detection thresholds were measured. We hypothesized that 1) auditory nerve fiber deafferentation increases forward masking thresholds and increases wave-V latency and 2) a preferential loss of low-spontaneous rate fibers results in a faster recovery of wave-V latency as the slow contribution of these fibers is reduced. Results showed that in young audiometrically normal listeners, a larger change in wave-V latency with increasing masker-to-probe interval was related to a greater effect of a preceding masker behaviorally. Further, the amount of wave-V latency change with masker-to-probe interval was positively correlated with the rate of change in forward masking detection thresholds. Although we cannot rule out central contributions, these findings are consistent with the hypothesis that auditory nerve fiber deafferentation occurs in humans and may predict how well individuals can hear in noisy environments.
Program in Speech and Hearing Bioscience and Technology, Harvard University-Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Center for Computational Neuroscience and Neural Technology, Boston University, Boston, MA, 02215, USA; Hearing Systems Group, Technical University of Denmark, Ørsteds Plads Building 352, 2800, Kongens Lyngby, Denmark. Electronic address: golmeh@elektro.dtu.dk.
Golbarg
G
Mehraei
Hearing Systems Group, Technical University of Denmark, Ørsteds Plads Building 352, 2800, Kongens Lyngby, Denmark.
Andreu Paredes
AP
Gallardo
Program in Speech and Hearing Bioscience and Technology, Harvard University-Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Center for Computational Neuroscience and Neural Technology, Boston University, Boston, MA, 02215, USA; Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA.
Barbara G
BG
Shinn-Cunningham
Hearing Systems Group, Technical University of Denmark, Ørsteds Plads Building 352, 2800, Kongens Lyngby, Denmark.
Torsten
T
Dau
D000161:Acoustic Stimulation; D000328:Adult; D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001307:Auditory Perception / Q000502:physiology; D001309:Auditory Threshold / Q000502:physiology; D003051:Cochlea / Q000294:innervation / Q000502:physiology; D003056:Cochlear Nerve / Q000502:physiology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008959:Models, Neurological; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D055815:Young Adult
Auditory brainstem response; Cochlear synaptopathy; Forward masking; Hidden hearing loss