scholarly journals Transient peripheral vestibular hypofunction measured with vestibular short-latency evoked potentials following noise exposure in rats

2021 ◽  
Author(s):  
Courtney E Stewart ◽  
David Scott Bauer ◽  
Richard A Altschuler ◽  
William Michael King
Keyword(s):  
Sound Pressure ◽  
Evoked Potential ◽  
Noise Exposure ◽  
Short Latency ◽  
Onset Latency ◽  
Frequency Range ◽  
Vestibular Hypofunction ◽  
Sound Levels ◽  
Intense Noise ◽  
Band Limited

Exposure to 120 decibel sound pressure level (dB SPL) band-limited noise results in delayed onset latency and reduced vestibular short-latency evoked potential (VsEP) responses. These changes are still present four weeks after noise overstimulation. Noise induced hearing loss (NIHL) has been shown to vary in extent and duration based on noise intensity. This study investigated whether noise-induced peripheral vestibular hypofunction (NPVH) would also decrease in extent and/or duration with less intense noise exposure. In the present study, rats were exposed to a less intense noise (110dB SPL), but for the same duration (6 hours) and frequency range (500-4000 Hz) as used in previous studies. The VsEP was assessed 1, 3, 7, 14, 21, and 28 days after noise exposure. In contrast to 120 dB SPL noise exposure, the 110 dB SPL noise exposures produced smaller deficits in VsEP responses that fully recovered in 62% of animals (13/21) within one week. These findings suggest that NPVH, a loss or attenuation of VsEP responses with a requirement for elevated stimulus intensity to elicit measurable responses, is similar to NIHL, i.e., lower sound levels produce a smaller or transient deficit. These results show it will be important to determine the extent and duration of vestibular hypofunction for different noise exposure conditions and their impact on balance.

scholarly journals Intense noise exposure alters peripheral vestibular structures and physiology

2020 ◽  
Vol 123 (2) ◽  
pp. 658-669 ◽  
Author(s):  
C. E. Stewart ◽  
D. S. Bauer ◽  
A. C. Kanicki ◽  
R. A. Altschuler ◽  
W. M. King
Keyword(s):  
Hair Cells ◽  
Evoked Potential ◽  
Noise Exposure ◽  
Critical Role ◽  
Short Latency ◽  
Synaptic Function ◽  
Otolith Organs ◽  
Large Head ◽  
Intense Noise ◽  
Afferent Terminals

The otolith organs play a critical role in detecting linear acceleration and gravity to control posture and balance. Some afferents that innervate these structures can be activated by sound and are at risk for noise overstimulation. A previous report demonstrated that noise exposure can abolish vestibular short-latency evoked potential (VsEP) responses and damage calyceal terminals. However, the stimuli that were used to elicit responses were weaker than those established in previous studies and may have been insufficient to elicit VsEP responses in noise-exposed animals. The goal of this study was to determine the effect of an established noise exposure paradigm on VsEP responses using large head-jerk stimuli to determine if noise induces a stimulus threshold shift and/or if large head-jerks are capable of evoking VsEP responses in noise-exposed rats. An additional goal is to relate these measurements to the number of calyceal terminals and hair cells present in noise-exposed vs. non-noise-exposed tissue. Exposure to intense continuous noise significantly reduced VsEP responses to large stimuli and abolished VsEP responses to small stimuli. This finding confirms that while measurable VsEP responses can be elicited from noise-lesioned rat sacculi, larger head-jerk stimuli are required, suggesting a shift in the minimum stimulus necessary to evoke the VsEP. Additionally, a reduction in labeled calyx-only afferent terminals was observed without a concomitant reduction in the overall number of calyces or hair cells. This finding supports a critical role of calretinin-expressing calyceal-only afferents in the generation of a VsEP response. NEW & NOTEWORTHY This study identifies a change in the minimum stimulus necessary to evoke vestibular short-latency evoked potential (VsEP) responses after noise-induced damage to the vestibular periphery and reduced numbers of calretinin-labeled calyx-only afferent terminals in the striolar region of the sacculus. These data suggest that a single intense noise exposure may impact synaptic function in calyx-only terminals in the striolar region of the sacculus. Reduced calretinin immunolabeling may provide insight into the mechanism underlying noise-induced changes in VsEP responses.

Duration tuning in the inferior colliculus of the mustached bat

2011 ◽  
Vol 106 (6) ◽  
pp. 3119-3128 ◽  
Author(s):  
Silvio Macías ◽  
Emanuel C. Mora ◽  
Julio C. Hechavarría ◽  
Manfred Kössl
Keyword(s):  
Inferior Colliculus ◽  
Sound Pressure ◽  
Frequency Range ◽  
Constant Frequency ◽  
Third Harmonic ◽  
Mustached Bat ◽  
Pteronotus Parnellii ◽  
Sound Levels ◽  
Response Profile ◽  
Band Pass

We studied duration tuning in neurons of the inferior colliculus (IC) of the mustached bat. Duration-tuned neurons in the IC of the mustached bat fall into three main types: short (16 of 136), band (34 of 136), and long (29 of 136) pass. The remaining 51 neurons showed no selectivity for the duration of sounds. The distribution of best durations was double peaked with maxima around 3 and 17 ms, which correlate with the duration of the short frequency-modulated (FM) and the long constant-frequency (CF) signals emitted by Pteronotus parnellii. Since there are no individual neurons with a double-peaked duration response profile, both types of temporal processing seem to be well segregated in the IC. Most short- and band-pass units with best frequency in the CF2 range responded to best durations > 9 ms (66%, 18 of 27 units). However, there is no evidence for a bias toward longer durations as there is for neurons tuned to the frequency range of the FM component of the third harmonic, where 83% (10 of 12 neurons) showed best durations longer than 9 ms. In most duration-tuned neurons, response areas as a function of stimulus duration and intensity showed either V or U shape, with duration tuning retained across the range of sound levels tested. Duration tuning was affected by changes in sound pressure level in only six neurons. In all duration-tuned neurons, latencies measured at the best duration were longer than best durations, suggesting that behavioral decisions based on analysis of the duration of the pulses would not be expected to be complete until well after the stimulus has occurred.

scholarly journals Vestibular short-latency evoked potential abolished by low-frequency noise exposure in rats

2018 ◽  
Vol 119 (2) ◽  
pp. 662-667 ◽  
Author(s):  
Courtney E. Stewart ◽  
Ariane C. Kanicki ◽  
Richard A. Altschuler ◽  
W. M. King
Keyword(s):  
Evoked Potential ◽  
Noise Exposure ◽  
Low Frequency ◽  
Short Latency ◽  
Head Movements ◽  
Frequency Noise ◽  
Otolith Organs ◽  
Specific Class ◽  
Low Frequency Noise ◽  
Physiological Basis

The vestibular system plays a critical role in detection of head movements and is essential for normal postural control. Because of their anatomical proximity to the cochlea, the otolith organs are selectively exposed to sound pressure and are at risk for noise overstimulation. Clinical reports suggest a link between noise exposure and balance problems, but the structural and physiological basis for this linkage is not well understood. The goal of this study was to determine the effects of low-frequency noise (LFN) on the otolith organs by correlating changes in vestibular short-latency evoked potentials (VsEPs) with changes in saccular afferent endings following noise exposure. LFN exposure transiently abolished the VsEP and reduced the number of stained calyces within the sacculus. Although some recovery of the VsEP waveform could be observed within 3 days after noise, at 3 wk recovery was only partial in most animals, consistent with a reduced number of afferents with calyceal endings. These data show that a single intense noise exposure is capable of causing a vestibular deficit that appears to mirror the synaptic deficit associated with hidden hearing loss after noise-induced cochlear injury. NEW & NOTEWORTHY This is the first study to explore the effects of low-frequency high-intensity noise on vestibular short-latency evoked potential (VsEP) responses, which shows a linkage between attenuated noise-induced VsEPs and pathological changes to otolith organ afferents. This finding suggests a potential limitation of the VsEP for evaluation of vestibular dysfunction, since the VsEP measurement may assess the activity of a specific class rather than all afferents.

Noise exposure in orthopaedic practice: potential health risk

2004 ◽  
Vol 118 (6) ◽  
pp. 413-416 ◽  
Author(s):  
Ramzan Ullah ◽  
Neil Bailie ◽  
Sean Crowther ◽  
James Cullen
Keyword(s):  
Hearing Loss ◽  
Noise Exposure ◽  
Pure Tone Audiometry ◽  
Speech Discrimination ◽  
Potential Health ◽  
Recorded Sound ◽  
Sound Levels ◽  
Service Staff ◽  
Intense Noise ◽  
Hearing Assessment

Noise exposure is one of the major causes of permanent hearing loss in society. Exposure of health service staff to intense levels of noise in the workplace is a potential risk for the development of temporary and permanent hearing loss.In this prospective study, 18 members of the orthopaedic staff underwent hearing assessment by pure tone audiometry and speech discrimination prior to noise exposure at the workplace and immediately following cessation of work. The number of hours of exposure and noise levels in the workplace was also analysed.Only minimal temporary sensorineural threshold shifts were detected post-noise exposure. There was no change in speech discrimination scores and no individuals complained of tinnitus. The number of hours of exposure ranged from 1.5 to 8.5 hours (mean 5.2 hours). Recorded sound levels for instruments ranged from 119.6 dB at source to 73.1 decibels at 3 metres.Although high sound levels are recorded in the orthopaedic operating theatre, the intermittent nature exposure to the intense noise may protect staff against hearing loss, speech discrimination difficulties and tinnitus.

scholarly journals Improved Source Characteristics of a Handclap for Acoustic Measurements: Utilization of a Leather Glove

Acoustics ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 803-811
Author(s):  
Rick de Vos ◽  
Nikolaos M. Papadakis ◽  
Georgios E. Stavroulakis
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Low Frequency ◽  
Pressure Level ◽  
Acoustic Measurements ◽  
Frequency Range ◽  
Acoustic Parameters ◽  
Source Characteristics ◽  
Sound Levels ◽  
Engineering Practices

A handclap is a convenient and easily available source for room acoustic measurements. If used correctly (e.g., application of optimal hand configuration) it can provide usable results for the measurement of acoustic parameters, within an expected deviation. Its biggest drawbacks are the low sound pressure level (especially in the low frequency range) as well as its low repeatability. With this in mind, this paper explores the idea of testing a handclap with a glove in order to assess the effect on its source characteristics. For this purpose, measurements were performed with 12 participants wearing leather gloves. Sound levels were compared with simple handclaps without gloves, and between grouped results (overall A-weighted SPL, octave bands, 1/3 octave bands). Measurements were also performed several times to evaluate the effect on repeatability. Results indicate that the use of leather gloves can increase the sound levels of a handclap by 10 dB and 15 dB in the low frequency ranges (63 Hz and 125 Hz octave bands, respectively). Handclaps with leather gloves also point toward improved repeatability, particularly in the low-frequency part of the frequency spectrum. In conclusion, compared to simple handclaps without gloves, evidence from this study supports the concept that handclaps with leather gloves can be used in engineering practices for improved room acoustic measurements of room impulse response.

An Investigation of the Perception Thresholds of Band-Limited Low Frequency Noises: Influence of Bandwidth

2003 ◽  
Vol 22 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Yasunao Matsumoto ◽  
Yukio Takahashi ◽  
Setsuo Maeda ◽  
Hiroki Yamaguchi ◽  
Kazuhiro Yamada ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Low Frequency ◽  
Frequency Range ◽  
Pass Filter ◽  
Sound Pressure Levels ◽  
Pure Tones ◽  
Band Limited ◽  
The One ◽  
Frequency Weighting ◽  
40 Hz

Perception thresholds of complex low frequency noises have been investigated in a laboratory experiment. Sound pressure levels that were just perceptible by subjects were measured for three complex noises and three pure tones. The complex noises had a flat constant spectrum over the frequency range 2 to 10, 20, or 40 Hz and decreased at 15 dB per octave at higher frequencies. The frequencies of the pure tones used in this study were 10, 20 and 40 Hz. The perception thresholds were obtained using an all-pass filter, one-third octave band filters, and the G frequency weighting defined in ISO 7196. The G-weighted sound pressure levels obtained were compared with 100 dB which is described in ISO 7196 as the G-weighted level corresponding to the threshold of sounds in the frequency range 1 to 20 Hz. The perception thresholds of the pure tones measured in this study were comparable to the results available in various previous studies. The one-third octave sound pressure levels obtained for the thresholds of the complex noises appeared to be lower than the measured thresholds of the pure tones. The G-weighted sound pressure levels obtained for the thresholds of the complex noises appeared to be lower than 100 dB.

scholarly journals Exposure to Intense Noise Causes Vestibular Loss

2020 ◽  
Vol 185 (Supplement_1) ◽  
pp. 454-461
Author(s):  
Courtney E Stewart ◽  
Ariane C Kanicki ◽  
David S Bauer ◽  
Richard A Altschuler ◽  
W Michael King
Keyword(s):  
Evoked Potential ◽  
Noise Exposure ◽  
Repeated Measurements ◽  
Otolith Organs ◽  
Partial Recovery ◽  
Stimulation Threshold ◽  
Vestibular Loss ◽  
Increased Risk ◽  
Intense Noise ◽  
The Military

ABSTRACT Introduction The vestibular system is essential for normal postural control and balance. Because of their proximity to the cochlea, the otolith organs are vulnerable to noise. We previously showed that head jerks that evoke vestibular nerve activity were no longer capable of inducing a response after noise overstimulation. The present study adds a greater range of jerk intensities to determine if the response was abolished or required more intense stimulation (threshold shift). Materials and Methods Vestibular short-latency evoked potential (VsEP) measurements were taken before noise exposure and compared to repeated measurements taken at specific time points for 28 days after noise exposure. Calretinin was used to identify changes in calyx-only afferents in the sacculus. Results Results showed that more intense jerk stimuli could generate a VsEP, although it was severely attenuated relative to prenoise values. When the VsEP was evaluated 4 weeks after noise exposure, partial recovery was observed. Conclusion These data suggest that noise overstimulation, such as can occur in the military, could introduce an increased risk of imbalance that should be evaluated before returning a subject to situations that require normal agility and motion. Moreover, although there is recovery with time, some dysfunction persists for extended periods.

The influence of external conditions on sound pressure in the pistonphone at the infrasound frequency range

2020 ◽  
pp. 67-72
Author(s):  
A. V. Konkov ◽  
D. V. Golovin
Keyword(s):  
Environmental Conditions ◽  
Sound Pressure ◽  
Primary Method ◽  
Frequency Range ◽  
External Conditions ◽  
Numerical Estimations

The influence of environmental conditions on a sound pressure reproduced by the primary method in the measuring chambers of the Pistonphone in the frequency range from 1 mHz to 250 Hz is estimated. Numerical estimations of influence of environmental conditions on sound pressure in pistonphone measuring chambers are given and special requirements to system of maintenance of required external conditions are specified.

scholarly journals 303 What goes bump in the night? A literature review and noise exposure experiment in a UK paediatric emergency department

2020 ◽  
Vol 37 (12) ◽  
pp. 841.1-841
Author(s):  
Lucy Hall ◽  
Sophie Dando ◽  
Anthony Hanks
Keyword(s):  
Emergency Department ◽  
Literature Review ◽  
Literature Search ◽  
Noise Exposure ◽  
Cochrane Library ◽  
Noise Levels ◽  
Paediatric Emergency Department ◽  
Paediatric Emergency ◽  
Sound Levels ◽  
Exposure Experiment

Aims/Objectives/BackgroundIn the Emergency department (ED), noise is a frequent and often unavoidable consequence of work undertaken and levels can often be raised during the day and night. Raised ambient noise levels have potential implications for the workforce, patients and relatives.Investigation into the problem of noise levels in the ED follows feedback from a young patient who couldn’t sleep during a prolonged stay. His complaint focused on loud, irregular banging noises such as those from closing bins that kept him awake.The team felt work should be done to see if it was a wider spread problem or just isolated to his case. A simple sound recording experiment and literature search was conducted.Methods/DesignThe literature search was conducted using electronic/online databases (Medline; Cochrane library) with a fixed date range and specific inclusion criteria.The noise exposure experiment was conducted using a verified phone app to record the sound levels. They were measured at 3 times, during a night shift, in the paediatric emergency department of UHW. All measurements were at a fixed distance and were averaged and compared with WHO recommendations.Results/ConclusionsThere are many sources of noise pollution in the ED, some are unavoidable for safety and clinical reasons.The literature review produced a small number of papers all of which found that sound levels were raised above recommended levels. Similarly, all the sounds measured in the ED also exceeded the recommendations.The most consistent finding across the papers, matched by findings from recordings, was that human behavioural modification is an easy and effective way to reduce noise levels.There are simple steps that can be taken to reduce and eliminate soundsRaising awareness regarding this problem is of great importance and focussing future work on assessing the impact in younger patients within the Emergency Department is paramount.

Medial Olivocochlear Reflex Effects on Amplitude Growth Functions of Long- and Short-Latency Components of Click-Evoked Otoacoustic Emissions in Humans

2021 ◽  
Author(s):  
Shawn Goodman ◽  
Sriram Boothalingam ◽  
Jeffery T Lichtenhan
Keyword(s):  
Otoacoustic Emissions ◽  
Dynamic Range ◽  
Short Latency ◽  
Medial Olivocochlear Reflex ◽  
Time Frequency ◽  
Growth Functions ◽  
Sound Levels ◽  
Amplitude Attenuation ◽  
Slope Change ◽  
Medial Olivocochlear

Functional outcomes of medial olivocochlear reflex (MOCR) activation, such as improved hearing in background noise and protection from noise damage, involve moderate to high sound levels. Previous noninvasive measurements of MOCR in humans focused primarily on otoacoustic emissions (OAEs) evoked at low sound levels. Interpreting MOCR effects on OAEs at higher levels is complicated by the possibility of the middle-ear muscle reflex and by components of OAEs arising from different locations along the length of the cochlear spiral. We overcame these issues by presenting click stimuli at a very slow rate and by time-frequency windowing the resulting click-evoked (CE)OAEs into short-latency (SL) and long-latency (LL) components. We characterized the effects of MOCR on CEOAE components using multiple measures to more comprehensively assess these effects throughout much of the dynamic range of hearing. These measures included CEOAE amplitude attenuation, equivalent input attenuation, phase, and slope of growth functions. Results show that MOCR effects are smaller on SL components than LL components, consistent with SL components being generated slightly basal of the characteristic frequency region. Amplitude attenuation measures showed the largest effects at the lowest stimulus levels, but slope change and equivalent input attenuation measures did not decrease at higher stimulus levels. These latter measures are less commonly reported and may provide insight into the variability in listening performance and noise susceptibility seen across individuals.

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