Intrinsic noise improves speech recognition in a computational model of the auditory pathway

AbstractNoise is generally considered to harm information processing performance. However, in the context of stochastic resonance, noise has been shown to improve signal detection of weak subthreshold signals, and it has been proposed that the brain might actively exploit this phenomenon. Especially within the auditory system, recent studies suggest that intrinsic noise plays a key role in signal processing and might even correspond to increased spontaneous neuronal firing rates observed in early processing stages of the auditory brain stem and cortex after hearing loss. Here we present a computational model of the auditory pathway based on a deep neural network, trained on speech recognition. We simulate different levels of hearing loss and investigate the effect of intrinsic noise. Remarkably, speech recognition after hearing loss actually improves with additional intrinsic noise. This surprising result indicates that intrinsic noise might not only play a crucial role in human auditory processing, but might even be beneficial for contemporary machine learning approaches.

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Influence of Age at Cochlear Implantation and Frequency-to-Place Mismatch on Early Speech Recognition in Adults

Otolaryngology ◽

10.1177/0194599820911707 ◽

2020 ◽

Vol 162 (6) ◽

pp. 926-932

Author(s):

Michael W. Canfarotta ◽

Brendan P. O’Connell ◽

Emily Buss ◽

Harold C. Pillsbury ◽

Kevin D. Brown ◽

...

Keyword(s):

Older Adults ◽

Speech Recognition ◽

Auditory Processing ◽

Present Report ◽

Spiral Ganglion ◽

Auditory Pathway ◽

Electrode Arrays ◽

Insertion Depth ◽

Tertiary Referral Center ◽

Contact Frequency

Objective Default frequency filters of cochlear implant (CI) devices assign frequency information irrespective of intracochlear position, resulting in varying degrees of frequency-to-place mismatch. Substantial mismatch negatively influences speech recognition in postlingually deafened CI recipients, and acclimatization may be particularly challenging for older adults due to effects of aging on the auditory pathway. The present report investigated the influence of mismatch and age at implantation on speech recognition within the initial 6 months of CI use. Study Design Retrospective review. Setting Tertiary referral center. Subjects and Methods Forty-eight postlingually deafened adult CI recipients of lateral wall electrode arrays underwent postoperative computed tomography to determine angular insertion depth of each electrode contact. Frequency-to-place mismatch was determined by comparing spiral ganglion place frequencies to default frequency filters. Consonant-nucleus-consonant (CNC) scores in the CI-alone condition at 1, 3, and 6 months postactivation were compared to the degree of mismatch at 1500 Hz and age at implantation. Results Younger adult CI recipients experienced more rapid growth in speech recognition during the initial 6 months postactivation. Greater degrees of frequency-to-place mismatch were associated with poorer performance, yet older listeners were not particularly susceptible to this effect. Conclusions While older adults are not necessarily more sensitive to detrimental effects of frequency-to-place mismatch, other factors appear to limit early benefit with a CI in this population. These results suggest that minimizing mismatch could optimize outcomes in adult CI recipients across the life span, which may be particularly beneficial in the elderly considering auditory processing deficits associated with advanced age.

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Speech-evoked Brainstem Auditory Responses and Auditory Processing Skills: A Correlation in Adults with Hearing Loss

International Archives of Otorhinolaryngology ◽

10.1055/s-0037-1603109 ◽

2017 ◽

Vol 22 (01) ◽

pp. 038-044 ◽

Cited By ~ 2

Author(s):

Taissane Sanguebuche ◽

Bruna Peixe ◽

Rúbia Bruno ◽

Eliara Biaggio ◽

Michele Garcia

Keyword(s):

Hearing Loss ◽

Auditory Processing ◽

Auditory Pathway ◽

Gap Detection ◽

Behavioral Tests ◽

Behavioral Skills ◽

Auditory Responses ◽

Level Difference ◽

Masking Level Difference ◽

Brainstem Response

Introduction The auditory system consists of sensory structures and central connections. The evaluation of the auditory pathway at a central level can be performed through behavioral and electrophysiological tests, because they are complementary to each other and provide important information about comprehension. Objective To correlate the findings of speech brainstem-evoked response audiometry with the behavioral tests Random Gap Detection Test and Masking Level Difference in adults with hearing loss. Methods All patients were submitted to a basic audiological evaluation, to the aforementioned behavioral tests, and to an electrophysiological assessment, by means of click-evoked and speech-evoked brainstem response audiometry. Results There were no statistically significant values among the electrophysiological test and the behavioral tests. However, there was a significant correlation between the V and A waves, as well as the D and F waves, of the speech-evoked brainstem response audiometry peaks. Such correlations are positive, indicating that the increase of a variable implies an increase in another and vice versa. Conclusion It was possible to correlate the findings of the speech-evoked brainstem response audiometry with those of the behavioral tests Random Gap Detection and Masking Level Difference. However, there was no statistically significant correlation between them. This shows that the electrophysiological evaluation does not depend uniquely on the behavioral skills of temporal resolution and selective attention.

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Disturbed Balance of Inhibitory Signaling Links Hearing Loss and Cognition

Frontiers in Neural Circuits ◽

10.3389/fncir.2021.785603 ◽

2022 ◽

Vol 15 ◽

Author(s):

Marlies Knipper ◽

Wibke Singer ◽

Kerstin Schwabe ◽

Gisela E. Hagberg ◽

Yiwen Li Hegner ◽

...

Keyword(s):

Hearing Loss ◽

Inhibitory Activity ◽

Auditory Processing ◽

Gain Control ◽

Auditory Pathway ◽

Adjustment Processes ◽

Age Dependent ◽

Inhibitory Strength ◽

Processing Deficits ◽

Neural Gain

Neuronal hyperexcitability in the central auditory pathway linked to reduced inhibitory activity is associated with numerous forms of hearing loss, including noise damage, age-dependent hearing loss, and deafness, as well as tinnitus or auditory processing deficits in autism spectrum disorder (ASD). In most cases, the reduced central inhibitory activity and the accompanying hyperexcitability are interpreted as an active compensatory response to the absence of synaptic activity, linked to increased central neural gain control (increased output activity relative to reduced input). We here suggest that hyperexcitability also could be related to an immaturity or impairment of tonic inhibitory strength that typically develops in an activity-dependent process in the ascending auditory pathway with auditory experience. In these cases, high-SR auditory nerve fibers, which are critical for the shortest latencies and lowest sound thresholds, may have either not matured (possibly in congenital deafness or autism) or are dysfunctional (possibly after sudden, stressful auditory trauma or age-dependent hearing loss linked with cognitive decline). Fast auditory processing deficits can occur despite maintained basal hearing. In that case, tonic inhibitory strength is reduced in ascending auditory nuclei, and fast inhibitory parvalbumin positive interneuron (PV-IN) dendrites are diminished in auditory and frontal brain regions. This leads to deficits in central neural gain control linked to hippocampal LTP/LTD deficiencies, cognitive deficits, and unbalanced extra-hypothalamic stress control. Under these conditions, a diminished inhibitory strength may weaken local neuronal coupling to homeostatic vascular responses required for the metabolic support of auditory adjustment processes. We emphasize the need to distinguish these two states of excitatory/inhibitory imbalance in hearing disorders: (i) Under conditions of preserved fast auditory processing and sustained tonic inhibitory strength, an excitatory/inhibitory imbalance following auditory deprivation can maintain precise hearing through a memory linked, transient disinhibition that leads to enhanced spiking fidelity (central neural gain⇑) (ii) Under conditions of critically diminished fast auditory processing and reduced tonic inhibitory strength, hyperexcitability can be part of an increased synchronization over a broader frequency range, linked to reduced spiking reliability (central neural gain⇓). This latter stage mutually reinforces diminished metabolic support for auditory adjustment processes, increasing the risks for canonical dementia syndromes.

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Aided Speech Recognition Abilities of Adults With a Severe or Severe-to-Profound Hearing Loss

Journal of Speech Language and Hearing Research ◽

10.1044/jslhr.4102.285 ◽

1998 ◽

Vol 41 (2) ◽

pp. 285-299 ◽

Cited By ~ 18

Author(s):

Mark C. Flynn ◽

Richard C. Dowell ◽

Graeme M. Clark

Keyword(s):

Hearing Loss ◽

Speech Recognition ◽

Profound Hearing Loss

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Effects of Mild Hearing Loss on Auditory Processing

Otolaryngologic Clinics of North America ◽

10.1016/s0030-6665(20)31872-7 ◽

1985 ◽

Vol 18 (2) ◽

pp. 337-344 ◽

Cited By ~ 3

Author(s):

Marion P. Downs

Keyword(s):

Hearing Loss ◽

Auditory Processing ◽

Mild Hearing Loss

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Neural Mechanisms of Music and Language

The Oxford Handbook of Neurolinguistics ◽

10.1093/oxfordhb/9780190672027.013.35 ◽

2019 ◽

pp. 906-952

Author(s):

Mattson Ogg ◽

L. Robert Slevc

Keyword(s):

Auditory Cortex ◽

Language Processing ◽

Auditory Processing ◽

Cortical Plasticity ◽

Speaker Identification ◽

Auditory Pathway ◽

Cognitive Mechanisms ◽

Cross Domain ◽

Music And Language ◽

Cortical Regions

Music and language are uniquely human forms of communication. What neural structures facilitate these abilities? This chapter conducts a review of music and language processing that follows these acoustic signals as they ascend the auditory pathway from the brainstem to auditory cortex and on to more specialized cortical regions. Acoustic, neural, and cognitive mechanisms are identified where processing demands from both domains might overlap, with an eye to examples of experience-dependent cortical plasticity, which are taken as strong evidence for common neural substrates. Following an introduction describing how understanding musical processing informs linguistic or auditory processing more generally, findings regarding the major components (and parallels) of music and language research are reviewed: pitch perception, syntax and harmonic structural processing, semantics, timbre and speaker identification, attending in auditory scenes, and rhythm. Overall, the strongest evidence that currently exists for neural overlap (and cross-domain, experience-dependent plasticity) is in the brainstem, followed by auditory cortex, with evidence and the potential for overlap becoming less apparent as the mechanisms involved in music and speech perception become more specialized and distinct at higher levels of processing.

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Defining the Role of Attention in Hierarchical Auditory Processing

Audiology Research ◽

10.3390/audiolres11010012 ◽

2021 ◽

Vol 11 (1) ◽

pp. 112-128

Author(s):

Caitlin N. Price ◽

Deborah Moncrieff

Keyword(s):

Auditory Processing ◽

Auditory Pathway ◽

Simultaneous Recording ◽

Neural Encoding ◽

Top Down ◽

Attentional Processes ◽

Clinical Interventions ◽

Speech In Noise ◽

Behavioral Studies ◽

Electrophysiological Studies

Communication in noise is a complex process requiring efficient neural encoding throughout the entire auditory pathway as well as contributions from higher-order cognitive processes (i.e., attention) to extract speech cues for perception. Thus, identifying effective clinical interventions for individuals with speech-in-noise deficits relies on the disentanglement of bottom-up (sensory) and top-down (cognitive) factors to appropriately determine the area of deficit; yet, how attention may interact with early encoding of sensory inputs remains unclear. For decades, attentional theorists have attempted to address this question with cleverly designed behavioral studies, but the neural processes and interactions underlying attention’s role in speech perception remain unresolved. While anatomical and electrophysiological studies have investigated the neurological structures contributing to attentional processes and revealed relevant brain–behavior relationships, recent electrophysiological techniques (i.e., simultaneous recording of brainstem and cortical responses) may provide novel insight regarding the relationship between early sensory processing and top-down attentional influences. In this article, we review relevant theories that guide our present understanding of attentional processes, discuss current electrophysiological evidence of attentional involvement in auditory processing across subcortical and cortical levels, and propose areas for future study that will inform the development of more targeted and effective clinical interventions for individuals with speech-in-noise deficits.

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Monitoring of the auditory pathway maturation after early intervention during the first year of life in infants with sensorineural hearing loss

European Archives of Oto-Rhino-Laryngology ◽

10.1007/s00405-020-06498-3 ◽

2020 ◽

Author(s):

F. Matin ◽

S. Haumann ◽

W. Roßberg ◽

D. Mitovska ◽

T. Lenarz ◽

...

Keyword(s):

Hearing Loss ◽

Early Intervention ◽

Hearing Aids ◽

Hearing Threshold ◽

Auditory Pathway ◽

Auditory Brainstem Responses ◽

First Year ◽

Early Therapy ◽

Hearing Thresholds ◽

First Year Of Life

Abstract Purpose The objective of this study was to investigate the auditory pathway maturation monitored by auditory brainstem responses (ABR) in infants with hearing loss during the first year of life. ABR were used to estimate hearing thresholds and the effect of early intervention strategies using hearing aids (HA). Methods Click-evoked ABRs were measured in 102 infants aged from 0 to 12 months to determine their individual auditory threshold. Early therapy intervention was recommended before 12 months of age and analyzed. To evaluate the effect of hearing amplification on auditory maturation, different subgroups of infants with moderate hearing loss were analyzed and the auditory pathway maturation was determined based on IPL I–V shortening. Results Overall, 110 ears (54.0% of 204 ears) with mild to profound HL showed threshold changes of 10 dB up to 60 dB in the follow-up ABR testing. HA were prescribed at the age of 3.8 ± 3.9 months. Cochlear implantation (CI) was performed in cases of repeated profound HL at the age of 9.9 months ± 4.5 months. A significant shortening of IPL I–V in all subgroups of infants (with and without risk factors) who received HA was shown and assumed auditory pathway maturation. Conclusion An early intervention using optimally fitted HA influenced auditory pathway maturation and may lead to improvements of hearing thresholds during the first year of life in infants. This study underscores the importance of not only providing HAs to infants, but also controlling for hearing threshold changes ensuring that HAs provide the optimal level of intervention or CI is indicated.

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