Simulating electrical modulation detection thresholds using a biophysical model of the auditory nerve

2016 ◽  
Vol 139 (5) ◽  
pp. 2448-2462 ◽  
Author(s):  
Gabrielle E. O'Brien ◽  
Nikita S. Imennov ◽  
Jay T. Rubinstein
Keyword(s):  
Auditory Nerve ◽  
Biophysical Model ◽  
Detection Thresholds ◽  
Electrical Modulation ◽  
Modulation Detection

scholarly journals Contrasting mechanisms for hidden hearing loss: Synaptopathy vs myelin defects

2021 ◽  
Vol 17 (1) ◽  
pp. e1008499
Author(s):  
Maral Budak ◽  
Karl Grosh ◽  
Aritra Sasmal ◽  
Gabriel Corfas ◽  
Michal Zochowski ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Animal Models ◽  
Hair Cell ◽  
Auditory Nerve ◽  
Auditory Neuropathy ◽  
Biophysical Model ◽  
Spiral Ganglion Neuron ◽  
High Threshold ◽  
Type I ◽  
Hidden Hearing Loss

Hidden hearing loss (HHL) is an auditory neuropathy characterized by normal hearing thresholds but reduced amplitudes of the sound-evoked auditory nerve compound action potential (CAP). In animal models, HHL can be caused by moderate noise exposure or aging, which induces loss of inner hair cell (IHC) synapses. In contrast, recent evidence has shown that transient loss of cochlear Schwann cells also causes permanent auditory deficits in mice with similarities to HHL. Histological analysis of the cochlea after auditory nerve remyelination showed a permanent disruption of the myelination patterns at the heminode of type I spiral ganglion neuron (SGN) peripheral terminals, suggesting that this defect could be contributing to HHL. To shed light on the mechanisms of different HHL scenarios observed in animals and to test their impact on type I SGN activity, we constructed a reduced biophysical model for a population of SGN peripheral axons whose activity is driven by a well-accepted model of cochlear sound processing. We found that the amplitudes of simulated sound-evoked SGN CAPs are lower and have greater latencies when heminodes are disorganized, i.e. they occur at different distances from the hair cell rather than at the same distance as in the normal cochlea. These results confirm that disruption of heminode positions causes desynchronization of SGN spikes leading to a loss of temporal resolution and reduction of the sound-evoked SGN CAP. Another mechanism resulting in HHL is loss of IHC synapses, i.e., synaptopathy. For comparison, we simulated synaptopathy by removing high threshold IHC-SGN synapses and found that the amplitude of simulated sound-evoked SGN CAPs decreases while latencies remain unchanged, as has been observed in noise exposed animals. Thus, model results illuminate diverse disruptions caused by synaptopathy and demyelination on neural activity in auditory processing that contribute to HHL as observed in animal models and that can contribute to perceptual deficits induced by nerve damage in humans.

scholarly journals Mammalian octopus cells are direction selective to frequency sweeps by synaptic sequence detection

2021 ◽  
Author(s):  
Hsin-Wei Lu ◽  
Philip H Smith ◽  
Philip Joris
Keyword(s):  
Auditory Nerve ◽  
Frequency Tuning ◽  
Direction Selectivity ◽  
Coincidence Detection ◽  
Biophysical Model ◽  
Projection Neurons ◽  
Sequence Detection ◽  
Frequency Sweeps ◽  
Activation Sequence

Octopus cells are remarkable projection neurons of the mammalian cochlear nucleus, with extremely fast membranes and wide frequency tuning. They are considered prime examples of coincidence detectors but are poorly characterized in vivo. We discover that octopus cells are selective to frequency sweep direction, a feature that is absent in their auditory nerve inputs. In vivo intracellular recordings reveal that direction selectivity does not derive from cross-channel coincidence detection but hinges on the amplitudes and activation sequence of auditory nerve inputs tuned to clusters of hotspot frequencies. A simple biophysical model of octopus cells excited with real nerve spike trains recreates direction selectivity through interaction of intrinsic membrane conductances with activation sequence of clustered inputs. We conclude that octopus cells are sequence detectors, sensitive to temporal patterns across cochlear frequency channels. The detection of sequences rather than coincidences is a much simpler but powerful operation to extract temporal information.

scholarly journals How Do Age and Hearing Loss Impact Spectral Envelope Perception?

2018 ◽  
Vol 61 (9) ◽  
pp. 2376-2385 ◽  
Author(s):  
Erol J. Ozmeral ◽  
Ann C. Eddins ◽  
David A. Eddins
Keyword(s):  
Hearing Loss ◽  
Spectral Resolution ◽  
Modulation Frequency ◽  
Normal Hearing ◽  
Frequency Resolution ◽  
Spectral Envelope ◽  
Detection Thresholds ◽  
Spectral Modulation ◽  
Modulation Detection ◽  
Moderate Hearing Loss

Purpose The goal was to evaluate the potential effects of increasing hearing loss and advancing age on spectral envelope perception. Method Spectral modulation detection was measured as a function of spectral modulation frequency from 0.5 to 8.0 cycles/octave. The spectral modulation task involved discrimination of a noise carrier (3 octaves wide from 400 to 3200 Hz) with a flat spectral envelope from a noise having a sinusoidal spectral envelope across a logarithmic audio frequency scale. Spectral modulation transfer functions (SMTFs; modulation threshold vs. modulation frequency) were computed and compared 4 listener groups: young normal hearing, older normal hearing, older with mild hearing loss, and older with moderate hearing loss. Estimates of the internal spectral contrast were obtained by computing excitation patterns. Results SMTFs for young listeners with normal hearing were bandpass with a minimum modulation detection threshold at 2 cycles/octave, and older listeners with normal hearing were remarkably similar to those of the young listeners. SMTFs for older listeners with mild and moderate hearing loss had a low-pass rather than a bandpass shape. Excitation patterns revealed that limited spectral resolution dictated modulation detection thresholds at high but not low spectral modulation frequencies. Even when factoring out (presumed) differences in frequency resolution among groups, the spectral envelope perception was worse for the group with moderate hearing loss than the other 3 groups. Conclusions The spectral envelope perception as measured by spectral modulation detection thresholds is compromised by hearing loss at higher spectral modulation frequencies, consistent with predictions of reduced spectral resolution known to accompany sensorineural hearing loss. Spectral envelope perception is not negatively impacted by advancing age at any spectral modulation frequency between 0.5 and 8.0 cycles/octave.

Modulation detection thresholds for cochlear implants: Dependence on stimulation site and stimulus level

2006 ◽  
Vol 120 (5) ◽  
pp. 3342-3342 ◽  
Author(s):  
Bryan E. Pfingst ◽  
Rose A. Burkholder ◽  
Catherine S. Thompson ◽  
Li Xu
Keyword(s):  
Cochlear Implants ◽  
Stimulus Level ◽  
Stimulation Site ◽  
Detection Thresholds ◽  
Modulation Detection

Effects of amplitude compression on first- and second-order modulation detection thresholds in cochlear implant listeners

2004 ◽  
Vol 43 (5) ◽  
pp. 264-270 ◽  
Author(s):  
Christian Lorenzi ◽  
Jérome Sibellas ◽  
Christian Füllgrabe ◽  
Stéphane Gallégo ◽  
Claude Fugain ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Second Order ◽  
Detection Thresholds ◽  
Amplitude Compression ◽  
Modulation Detection

scholarly journals The effect of presentation level on spectrotemporal modulation detection

2018 ◽  
Author(s):  
Sara Magits ◽  
Arturo Moncada-Torres ◽  
Lieselot Van Deun ◽  
Jan Wouters ◽  
Astrid van Wieringen ◽  
...  
Keyword(s):  
Computational Model ◽  
Neural Activity ◽  
Auditory Nerve ◽  
Normal Hearing ◽  
Behavioral Data ◽  
Speech In Noise ◽  
Presentation Level ◽  
Modulation Detection

AbstractThe understanding of speech in noise relies (at least partially) on spectrotemporal modulation sensitivity. This sensitivity can be measured by spectral ripple tests, which can be administered at different presentation levels. However, it is not known how presentation level affects spectrotemporal modulation thresholds. In this work, we present behavioral data for normal-hearing adults which show that at higher ripple densities (2 and 4 ripples/oct), increasing presentation level led to worse discrimination thresholds. Results of a computational model suggested that the higher thresholds could be explained by a worsening of the spectrotemporal representation in the auditory nerve due to broadening of cochlear filters and neural activity saturation. Our results demonstrate the importance of taking presentation level into account when administering spectrotemporal modulation detection tests.

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