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The Journal of the Acoustical Society... Oct 2023Ambient noise constrains the evolution of acoustic signals and hearing. An earlier fitness model showed that the trade-off between sound detection and recognition helps...
Ambient noise constrains the evolution of acoustic signals and hearing. An earlier fitness model showed that the trade-off between sound detection and recognition helps predict the best level of auditory sensitivity for acoustic communication in noise. Here, the early model is improved to investigate the effects of different noise masking conditions and signal-to-noise ratios (SNRs). It is revealed that low sensitivity is expected for acoustic communication over short distances in complex noisy environments provided missed sound recognition is costly. By contrast, high sensitivity is expected for acoustic communication over long distances in quieter habitats or when sounds are received with good SNRs under unfavorable noise conditions. High sensitivity is also expected in noisy environments characterized by one dominant source of noise with a fairly constant spectrum (running-water noise) or when sounds are processed using anti-masking strategies favoring the detection and recognition of sound embedded in noise. These predictions help explain unexpected findings that do not fit with the current view on the effects of environmental selection on signal and sensitivity. Model predictions are compared with those of models of signal detection in noisy conditions and results of empirical studies.
Topics: Noise; Hearing; Ecosystem; Acoustics; Hearing Tests; Perceptual Masking; Acoustic Stimulation
PubMed: 37819375
DOI: 10.1121/10.0021306 -
Hearing Research Sep 2023Cross-head transmission inherent in bone conduction (BC) hearing is one of the most important factors that limit the performance of BC binaural hearing compared to air...
Cross-head transmission inherent in bone conduction (BC) hearing is one of the most important factors that limit the performance of BC binaural hearing compared to air conduction (AC) binaural hearing. In AC, cross-head transmission is imperceptible leading to a clear understanding of the nature and position of the sound source(s). In this study, the prominence of cross-head transmission in BC hearing is addressed using the fact that ipsilateral cochlear excitation can be canceled by controlled bilateral BC stimulation. A cancellation experiment was conducted on twenty participants with normal hearing at thirteen third-octave frequencies between 250 and 4000 Hz. Both stationary and transient BC stimulation at the mastoid was used. The technique employed multiple stages of masking enabling adjustments of the stimulation level and phase until the tones got canceled in the ipsilateral ear. In addition, the ear canal sound pressure was obtained for ipsilateral and contralateral BC stimulation in isolation, and with bilateral BC stimulation at perceptual cancellation. The inter-aural level differences of both the types of stimulations were found to be the same. Crosstalk was found to be the lowest around 2 kHz and the highest around 1 kHz. The unwrapped inter-aural phase difference from stationary signal cancellation showed an overall increase with frequency starting at around no difference (35°) at 250 Hz to reach 607° at 4 kHz. Cycle-adjusted inter-aural time difference was very low (61 µs) at 250 Hz and increased to 1.1 ms at 800 Hz before falling to 0.6 ms at 4 kHz. It was also found that the ear canal sound pressure was not cancelled at the same phase as the sound in the cochlea.
Topics: Humans; Bone Conduction; Acoustic Stimulation; Hearing; Sound; Cochlea
PubMed: 37463528
DOI: 10.1016/j.heares.2023.108852 -
International Journal of Audiology Jun 2024The objective of this study is to determine the noise effective masking level (EML) and inter-aural attenuation (IA) for click and CE-Chirp signals presented though a...
OBJECTIVE
The objective of this study is to determine the noise effective masking level (EML) and inter-aural attenuation (IA) for click and CE-Chirp signals presented though a Radioear B-81 to elicit the auditory brainstem responses in normally hearing, young adults.
DESIGN AND STUDY SAMPLE
A total of 26 conveniently sampled adults (13 male and 13 female, aged 18-25 years; 52 ears), with pure-tone hearing thresholds not >15 dB nHL at octave frequencies from 250 to 8000 Hz, and subjective thresholds for the bone-conducted click and CE-Chirp not >10 dB nHL.
RESULTS
At stimulus intensities of 30 and 40 dB nHL, the contralateral EML was 67.86 ± 0.78 and 77.80 ± 0.81 dB SPL (respectively) for the click and 72.11 ± 0.74 and 83.53 ± 0.78 dB SPL (respectively) for the CE-Chirp. At stimulus intensities of 30 and 40 dB nHL, the IA was 3.46 ± 2.34 and 3.38 ± 2.03 dB (respectively) for both the click and the CE-Chirp.
CONCLUSION
EML and IA values are reported for click and CE-Chirp signals presented at 30 and 40 dB nHL though a Radioear B-81 to elicit the ABR in normally hearing, young adults.
Topics: Humans; Female; Adult; Male; Young Adult; Bone Conduction; Perceptual Masking; Auditory Threshold; Adolescent; Acoustic Stimulation; Noise; Audiometry, Pure-Tone; Evoked Potentials, Auditory, Brain Stem; Time Factors; Hearing
PubMed: 37083104
DOI: 10.1080/14992027.2023.2197145 -
Scientific Reports Nov 2023Previous research has shown that neural activity in the primary visual cortex (V1) and V1 surface area may be linked with subjective experience of size illusions. Here,...
Previous research has shown that neural activity in the primary visual cortex (V1) and V1 surface area may be linked with subjective experience of size illusions. Here, we behaviorally measured the hallway illusion with experimental manipulations as a proxy of V1's influence on size perception. We first tested whether the hallway illusion can persist without further recurrent processing by using backward masking. Next, we examined relations among the hallway illusion magnitude and other perceptual measures that have been suggested to be correlated with V1 surface area. In Experiment 1, the magnitude of the hallway illusion was not affected by the stimulus duration and visual masking when the hallway context was previewed (i.e., complex depth information is already processed). It suggests that V1 activity could support the size illusion to some extent even when recurrent processing between V1 and higher areas is disturbed. In Experiment 2, the hallway illusion magnitude was correlated with the Vernier acuity threshold, but not with physical size discriminability. Our results provide converging evidence with the previous findings in that neural activity in V1 may contribute to size illusions and that V1 surface area is not the sole factor that mediates size perception and visual precision.
Topics: Humans; Illusions; Visual Cortex; Primary Visual Cortex; Photic Stimulation; Size Perception; Visual Perception
PubMed: 38036762
DOI: 10.1038/s41598-023-48632-1 -
The European Journal of Neuroscience Sep 2023Visual perception is formed over time through the formation process and visual pathway. Exercise improves visual perception, but it is unclear whether exercise modulates...
Visual perception is formed over time through the formation process and visual pathway. Exercise improves visual perception, but it is unclear whether exercise modulates nonspecifically or specifically the formation process and pathway of visual perception. Healthy young men performed the visual detection task in a backward masking paradigm before and during cycling exercise at a mild intensity or rest (control). The task presented gratings of a circular patch (target) and annulus (mask) arranged concentrically as a visual stimulus and asked if the presence and striped pattern (feature) of the target were detected. The relationship between the orientations of the gratings of the target and the mask included iso-orientation and orthogonal orientation to investigate the orientation selectivity of the masking effect. The masking effect was evaluated by perceptual suppressive index (PSI). Exercise improved feature detection (∆PSI; Exercise: -20.6%, Control: 1.7%) but not presence detection (∆PSI; Exercise: 8.9%, Control: 29.6%) compared to the control condition, and the improving effect resulted from the attenuation of the non-orientation-selective (∆PSI; Exercise: -29.0%, Control: 16.8%) but not orientation-selective masking effect (∆PSI; Exercise: -3.1%, Control: 11.7%). These results suggest that exercise affects the formation process of the perceptual feature of the target stimulus by suppressively modulating the neural networks responsible for the non-orientation-selective surround interaction in the subcortical visual pathways, whose effects are inherited by the cortical visual pathways necessary for perceptual image formation. In conclusion, our findings suggest that acute exercise improves visual perception transiently through the modulation of a specific formation process of visual processing.
Topics: Male; Humans; Perceptual Masking; Visual Cortex; Visual Perception; Exercise; Photic Stimulation
PubMed: 37424403
DOI: 10.1111/ejn.16082 -
European Archives of... Jul 2023Inter-aural insertion depth difference (IEDD) in bilateral cochlear implant (BiCI) with continuous interleaved sampling (CIS) processing is known to reduce the...
Effect of interaural electrode insertion depth difference and independent band selection on sentence recognition in noise and spatial release from masking in simulated bilateral cochlear implant listening.
PURPOSE
Inter-aural insertion depth difference (IEDD) in bilateral cochlear implant (BiCI) with continuous interleaved sampling (CIS) processing is known to reduce the recognition of speech in noise and spatial release from masking (SRM). However, the independent channel selection in the 'n-of-m' sound coding strategy might have a different effect on speech recognition and SRM when compared to the effects of IEDD in CIS-based findings. This study aimed to investigate the effect of bilateral 'n-of-m' processing strategy and interaural electrode insertion depth difference on speech recognition in noise and SRM under conditions that simulated bilateral cochlear implant listening.
METHODS
Five young adults with normal hearing sensitivity participated in the study. The target sentences were spatially filtered to originate from 0° and the masker was spatially filtered at 0°, 15°, 37.5°, and 90° using the Oldenburg head-related transfer function database for behind the ear microphone. A 22-channel sine wave vocoder processing based on 'n-of-m' processing was applied to the spatialized target-masker mixture, in each ear. The perceptual experiment involved a test of speech recognition in noise under one co-located condition (target and masker at 0°) and three spatially separated conditions (target at 0°, masker at 15°, 37.5°, or 90° to the right ear).
RESULTS
The results were analyzed using a three-way repeated measure analysis of variance (ANOVA). The effect of interaural insertion depth difference (F (2,8) = 3.145, p = 0.098, ɳ = 0.007) and spatial separation between target and masker (F (3,12) = 1.239, p = 0.339, ɳ = 0.004) on speech recognition in noise was not significant.
CONCLUSIONS
Speech recognition in noise and SRM were not affected by IEDD ≤ 3 mm. Bilateral 'n-of-m' processing resulted in reduced speech recognition in noise and SRM.
Topics: Young Adult; Humans; Cochlear Implants; Speech Perception; Cochlear Implantation; Auditory Perception; Noise; Perceptual Masking
PubMed: 36695909
DOI: 10.1007/s00405-023-07845-w -
The Journal of the Acoustical Society... May 2024Medial olivocochlear (MOC) efferents modulate outer hair cell motility through specialized nicotinic acetylcholine receptors to support encoding of signals in noise....
Medial olivocochlear (MOC) efferents modulate outer hair cell motility through specialized nicotinic acetylcholine receptors to support encoding of signals in noise. Transgenic mice lacking the alpha9 subunits of these receptors (α9KOs) have normal hearing in quiet and noise, but lack classic cochlear suppression effects and show abnormal temporal, spectral, and spatial processing. Mice deficient for both the alpha9 and alpha10 receptor subunits (α9α10KOs) may exhibit more severe MOC-related phenotypes. Like α9KOs, α9α10KOs have normal auditory brainstem response (ABR) thresholds and weak MOC reflexes. Here, we further characterized auditory function in α9α10KO mice. Wild-type (WT) and α9α10KO mice had similar ABR thresholds and acoustic startle response amplitudes in quiet and noise, and similar frequency and intensity difference sensitivity. α9α10KO mice had larger ABR Wave I amplitudes than WTs in quiet and noise. Other ABR metrics of hearing-in-noise function yielded conflicting findings regarding α9α10KO susceptibility to masking effects. α9α10KO mice also had larger startle amplitudes in tone backgrounds than WTs. Overall, α9α10KO mice had grossly normal auditory function in quiet and noise, although their larger ABR amplitudes and hyperreactive startles suggest some auditory processing abnormalities. These findings contribute to the growing literature showing mixed effects of MOC dysfunction on hearing.
Topics: Animals; Female; Male; Mice; Acoustic Stimulation; Auditory Pathways; Auditory Perception; Auditory Threshold; Behavior, Animal; Cochlea; Evoked Potentials, Auditory, Brain Stem; Hearing; Mice, Inbred C57BL; Mice, Knockout; Noise; Olivary Nucleus; Perceptual Masking; Phenotype; Receptors, Nicotinic; Reflex, Startle
PubMed: 38738939
DOI: 10.1121/10.0025985 -
PloS One 2023Differences in spectro-temporal degradation may explain some variability in cochlear implant users' speech outcomes. The present study employs vocoder simulations on...
Differences in spectro-temporal degradation may explain some variability in cochlear implant users' speech outcomes. The present study employs vocoder simulations on listeners with typical hearing to evaluate how differences in degree of channel interaction across ears affects spatial speech recognition. Speech recognition thresholds and spatial release from masking were measured in 16 normal-hearing subjects listening to simulated bilateral cochlear implants. 16-channel sine-vocoded speech simulated limited, broad, or mixed channel interaction, in dichotic and diotic target-masker conditions, across ears. Thresholds were highest with broad channel interaction in both ears but improved when interaction decreased in one ear and again in both ears. Masking release was apparent across conditions. Results from this simulation study on listeners with typical hearing show that channel interaction may impact speech recognition more than masking release, and may have implications for the effects of channel interaction on cochlear implant users' speech recognition outcomes.
Topics: Humans; Cochlear Implants; Speech; Perceptual Masking; Speech Perception; Cochlear Implantation
PubMed: 37917727
DOI: 10.1371/journal.pone.0287728 -
Frontiers in Aging Neuroscience 2024Perceptual learning (PL) has shown promise in enhancing residual visual functions in patients with age-related macular degeneration (MD), however it requires prolonged...
Perceptual learning (PL) has shown promise in enhancing residual visual functions in patients with age-related macular degeneration (MD), however it requires prolonged training and evidence of generalization to untrained visual functions is limited. Recent studies suggest that combining transcranial random noise stimulation (tRNS) with perceptual learning produces faster and larger visual improvements in participants with normal vision. Thus, this approach might hold the key to improve PL effects in MD. To test this, we trained two groups of MD participants on a contrast detection task with ( = 5) or without ( = 7) concomitant occipital tRNS. The training consisted of a lateral masking paradigm in which the participant had to detect a central low contrast Gabor target. Transfer tasks, including contrast sensitivity, near and far visual acuity, and visual crowding, were measured at pre-, mid and post-tests. Combining tRNS and perceptual learning led to greater improvements in the trained task, evidenced by a larger increment in contrast sensitivity and reduced inhibition at the shortest target to flankers' distance. The overall amount of transfer was similar between the two groups. These results suggest that coupling tRNS and perceptual learning has promising potential applications as a clinical rehabilitation strategy to improve vision in MD patients.
PubMed: 38450381
DOI: 10.3389/fnagi.2024.1326435 -
PloS One 2023The study aimed to evaluate the effect of systemic cisplatin administration on off-frequency masking audiometry.
OBJECTIVE
The study aimed to evaluate the effect of systemic cisplatin administration on off-frequency masking audiometry.
METHODS
Among 26 patients receiving systemic cisplatin, 48 ears were included in the analysis. All patients underwent pure-tone audiometry with ipsilateral narrow-band masking noise (off-frequency masking audiometry). In the off-frequency masking audiometry, 70 dBHL band-pass noise (center frequency 1000 Hz, 1/3 octave bandwidth) was administered to the tested ear. The acquired thresholds were compared to those of standard pure-tone audiometry, and threshold elevations greater than 10 dB were regarded as significant. The number of patients showing abnormal threshold elevation was compared between before and after the cisplatin administration.
RESULTS
Before cisplatin administration, 91.7, 93.8, 97.9, and 93.8% of ears showed normal off-frequency masking audiometry outcomes at 125, 250, 6000, and 8000 Hz, respectively. After cisplatin administration, a higher number of patients showed abnormal off-frequency masking audiometry outcomes. This change was more prominent with increasing doses of cisplatin. After the cisplatin administration of 100∼200 mg/m2, the prevalence of patients with normal off-frequency masking audiometry outcomes was 77.3, 70.5, 90.9, and 88.6% at 125, 250, 6000, and 8000 Hz, respectively. At 250 Hz, the change was statistically significant (p = 0.01, chi-squared test).
Topics: Humans; Cisplatin; Auditory Threshold; Perceptual Masking; Audiometry; Audiometry, Pure-Tone; Noise
PubMed: 37410731
DOI: 10.1371/journal.pone.0287400