In mammals, localization of sound sources in azimuth depends on sensitivity to interaural differences timing (ITD) and level (ILD). Paradoxically, while typical ILD-sensitive neurons the auditory brainstem require millisecond synchrony excitatory inhibitory inputs for encoding ILDs, human animal behavioral ILD is robust temporal stimulus degradations (e.g., decorrelation due reverberation), or, humans, bilateral clinical device processing. Here we demonstrate that only modestly degraded with...

To reduce the amplitude of stimulus artefacts present in bone conduction auditory brainstem response (BC ABR) measurements. Electromagnetic shielding was applied to surface a clinical BC transducer. A foam pad also placed on shielded mastoid-contacting plate Acoustic impacts these modifications were evaluated using an artificial mastoid. Unmodified and modified (shielding with pad) transducers then used elicit ABRs adults infants. Stimulus artefact amplitudes compared across transducers. Six...

Temporal weighting functions (TWFs), quantifying sensitivity to interaural time differences (ITD) and level (ILD) over the duration of brief stimuli, were measured in 6 normal hearing subjects using trains 16 Gabor clicks centered at 4 kHz presented dichotically rates [inter-click intervals (ICI) 10, 5, 2.5, 1.25 ms]. Random ITD or ILD imposed independently on each click train separate conditions. The subject’s task was discriminate lateral position (“left” “right”). Receiver operating...

Hearing protection devices (HPDs) such as earplugs offer to mitigate noise exposure and reduce the incidence of hearing loss among persons frequently exposed intense sound. However, distortions spatial acoustic information reduced audibility low-intensity sounds caused by many existing HPDs can make their use untenable in high-risk (e.g., military or law enforcement) environments where auditory situational awareness is imperative. Here we assessed (1) sound source localization accuracy using...

Abstract We investigated the roles of swim bladder and lateral line system in sound localization behavior by plainfin midshipman fish (Porichthys notatus). Reproductive female underwent either surgical deflation or cryoablation were then tested a monopolar source task. Fish with nominally "deflated" bladders performed similar to sham-deflated controls; however, post-experiment evaluation revealed that majority (88%, 7 8 fish) exhibited positive phonotaxis had partially inflated bladders. In...

Temporal variation in listeners' sensitivity to interaural time and level differences (ITD ILD) was assessed using the temporal weighting function (TWF) paradigm [Stecker Hafter (2002). J. Acoust. Soc. Am. 112, 1046-1057] context of sound-source lateralization. Brief Gabor click trains were presented over headphones with overall ITD and/or ILD ranging ±500 μs ±5 dB across trials; values for individual clicks within each train varied by an additional ±100 or ±2 allow TWF calculation multiple...

Listeners detected interaural differences of time (ITDs) or level (ILDs) carried by single 4000-Hz Gabor clicks (Gaussian-windowed tone bursts) and trains 16 such repeating at an interclick interval (ICI) 2, 5, 10 ms. In separate conditions, target favored the right ear a constant amount for all (condition RR), attained their peak value onset diminished linearly to 0 offset R0), grew from 0R). Threshold ITDs ILDs were determined adaptively in experiments each these conditions clicks. ITD...

Despite identification of multiple factors mediating salmon survival, significant disparities in survival-to-adulthood among hatchery- versus wild-origin juveniles persist. In the present report, we explore hypothesis that hatchery-reared might exhibit morphological defects vulnerable mechanosensory systems prior to release from hatchery, potentiating reduced survival after release. Juvenile steelhead (Oncorhynchus mykiss) two different hatcheries were compared on several traits including...

The present investigation assessed fusion and localization dominance aspects of the precedence effect under headphones across a variety stimulus conditions in 10 normal-hearing listeners. Listeners were presented with “lead-lag” pairs brief (123 μs) impulses or trains such lateralized by interaural time level differences (ITD ILD). used touch-sensitive display to indicate for final lead-lag pair on each trial (1) whether one two locations perceived (2) location perceived. In event perceived,...

The century-old duplex theory of sound localization posits that low- and high-frequency sounds are localized with two different acoustical cues, interaural time level differences (ITDs ILDs), respectively. While behavioral studies in humans neurophysiological a variety animal models have largely supported the theory, sensitivity to ILD is curiously invariant across audible spectrum. Here we demonstrate auditory midbrain neurons chinchilla ( Chinchilla lanigera) also encode ILDs...

In patients with bilateral hearing loss, the use of two aids (HAs) offers potential to restore benefits binaural hearing, including sound source localization and segregation. However, existing evidence suggests that HA users’ access information, namely interaural time level differences (ITDs ILDs), can be compromised by device processing. Our objective was characterize nature magnitude distortions caused modern digital behind-the-ear HAs using a variety stimuli program settings. Of...

Hypothesis: Intracochlear pressures (P IC ) and stapes velocity (V stap elicited by bilaterally placed bone-anchored hearing devices (BAHD) will be systematically modulated imposed interaural time (ITD) level differences (ILD), demonstrating the potential for users of bilateral BAHD to access these binaural cues. Background: are traditionally implanted unilaterally under assumption that transcranial cross-talk limits differences. Recent studies have demonstrated improvements in spatial...

Normal-hearing human listeners and a variety of studied animal species localize sound sources accurately in reverberant environments by responding to the directional cues carried first-arriving rather than spurious later-arriving reflections, which are not perceived discretely. This phenomenon is known as precedence effect (PE) localization. Despite decades study, biological basis PE remains unclear. Though was once widely attributed central processes such synaptic inhibition auditory...

Whilst the hearing capabilities of ear are well known and extensively studied, less is fact that can produce sounds. These faint sounds called otoacoustic emissions an involuntary feature biomechanical system employed to hear low amplitude Several distinct types emission known; these, one particular type, transient (TEOAEs), shows potential as a biometric. This paper graphically presents examples TEOAEs demonstrate specificity individual their stability over six month period time. large...

Recent work has demonstrated that sensitivity to interaural time differences (ITD) carried by high-rate cochlear implant pulse trains or analogous acoustic signals can be enhanced imposing random temporal variation on the stimulus rate [see Goupell et al. (2009). J. Acoust. Soc. Am. 126, 2511–2521]. The present study characterized effect of such “temporal jitter” normal-hearing listeners’ weighting ITD and level (ILD) applied brief Gabor clicks (4 kHz center frequency) presented at nominal...

Acoustic hearing listeners use binaural cues—interaural time differences (ITDs) and interaural level (ILDs)—for localization segregation of sound sources in the horizontal plane. Cochlear implant users now often receive two implants (bilateral cochlear [BiCIs]) rather than one, with goal to provide access these cues. However, BiCI experience difficulty tasks. Most BiCIs independent processors at each ear; it has been suggested that such independence may degrade transmission cues,...

The relative sensitivity of human listeners to interaural level differences (ILDs) carried by the onsets, offsets, and interior portions brief sounds was examined. Stimuli consisted single 4000-Hz Gabor clicks (Gaussian-windowed tone bursts) or trains 16 such repeating at an interclick interval (ICI) 2 5 ms. In separate conditions, ILDs favored right ear a constant amount for all (condition RRRR) changing that maximal sound onset R000), offset 000R), both R00R), temporal midpoint stimulus...

A common way to assess the function of sensory neurons is measure number spikes produced by individual while systematically varying a given dimension stimulus. Such measured tuning curves can then be used quantify accuracy neural representation stimulus under study, which in turn related behavioral performance. However, often change shape when other dimensions are varied, reflecting simultaneous sensitivity multiple features. Here we illustrate how one-dimensional information analyses...

The auditory brain stem response (ABR) is an evoked potential that indexes a cascade of neural events elicited by sound. In the present study we evaluated influence sound frequency on derived component ABR known as binaural interaction (BIC). Specifically, effect acoustic interaural (between-ear) mismatch BIC amplitude. Goals were to

Abstract Early sensory experience can exert lasting perceptual consequences. For example, a brief period of auditory deprivation early in life lead to persistent spatial hearing deficits. Some forms loss (i.e., conductive; CHL) distort acoustical cues needed for hearing, which depend on inputs from both ears. We hypothesize that asymmetric acoustic input during development disrupts circuits integrate binaural information. Here, we identify prolonged maturation the brainstem guinea pig by...