Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
Time-varying auditory gain control in response to double-pulse stimuli in harbour porpoises is not mediated by a stapedial reflex. / Schroder, Asger Emil Munch; Beedholm, Kristian; Madsen, Peter Teglberg.
In: Open Biology, Vol. 6, No. 4, 15.04.2017, p. 525-529.Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
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TY - JOUR
T1 - Time-varying auditory gain control in response to double-pulse stimuli in harbour porpoises is not mediated by a stapedial reflex
AU - Schroder, Asger Emil Munch
AU - Beedholm, Kristian
AU - Madsen, Peter Teglberg
PY - 2017/4/15
Y1 - 2017/4/15
N2 - Echolocating animals reduce their output level and hearing sensitivity with decreasing echo delays, presumably to stabilize the perceived echo intensity during target approaches. In bats, this variation in hearing sensitivity is formed by a call-induced stapedial reflex that tapers off over time after the call. Here, we test the hypothesis that a similar mechanism exists in toothed whales by subjecting a trained harbour porpoise to a series of double sound pulses varying in delay and frequency, while measuring the magnitudes of the evoked auditory brainstem responses (ABRs). We find that the recovery of the ABR to the second pulse is frequency dependent, and that a stapedial reflex therefore cannot account for the reduced hearing sensitivity at short pulse delays. We propose that toothed whale auditory time-varying gain control during echolocation is not enabled by the middle ear as in bats, but rather by frequency-dependent mechanisms such as forward masking and perhaps higher-order control of efferent feedback to the outer hair cells.
AB - Echolocating animals reduce their output level and hearing sensitivity with decreasing echo delays, presumably to stabilize the perceived echo intensity during target approaches. In bats, this variation in hearing sensitivity is formed by a call-induced stapedial reflex that tapers off over time after the call. Here, we test the hypothesis that a similar mechanism exists in toothed whales by subjecting a trained harbour porpoise to a series of double sound pulses varying in delay and frequency, while measuring the magnitudes of the evoked auditory brainstem responses (ABRs). We find that the recovery of the ABR to the second pulse is frequency dependent, and that a stapedial reflex therefore cannot account for the reduced hearing sensitivity at short pulse delays. We propose that toothed whale auditory time-varying gain control during echolocation is not enabled by the middle ear as in bats, but rather by frequency-dependent mechanisms such as forward masking and perhaps higher-order control of efferent feedback to the outer hair cells.
KW - Toothed whale
KW - Echolocation
KW - Stapedial reflex
KW - Masking
KW - Automatic gain control
KW - Hearing
KW - BOTTLE-NOSED-DOLPHIN
KW - EVOKED-POTENTIAL RECOVERY
KW - DOUBLE CLICK STIMULATION
KW - FALSE KILLER WHALE
KW - HEARING SENSITIVITY
KW - PHOCOENA-PHOCOENA
KW - TURSIOPS-TRUNCATUS
KW - ECHOLOCATION
KW - SYSTEM
KW - BATS
U2 - 10.1242/bio.021469
DO - 10.1242/bio.021469
M3 - Journal article
C2 - 28202466
VL - 6
SP - 525
EP - 529
JO - Open Biology
JF - Open Biology
SN - 2046-2441
IS - 4
ER -