Underwater Hearing in the Frog, Rana Catesbeiana

1981 ◽  
Vol 91 (1) ◽  
pp. 57-71 ◽  
Author(s):  
R. ERIC LOMBARD ◽  
RICHARD R. FAY ◽  
YEHUDAH L. WERNER
Keyword(s):  
Sound Pressure ◽  
Rana Catesbeiana ◽  
Sound Intensity ◽  
Torus Semicircularis ◽  
Intensity Level ◽  
Hearing Thresholds ◽  
Average Loss ◽  
Two Measures ◽  
Underwater Hearing ◽  
Hearing Abilities

Comparable auditory sound pressure level (SPL) and sound intensity level(SIL) threshold curves were determined in air and under water in Ranacatesbeiana. Threshold curves were determined using chronic metal electrodeimplants which detected multi-unit responses of the torus semicircularis toincident sound. In terms of SPL, hearing thresholds in water and air aresimilar below 0.2 kHz. Above 0.2 kHz, the sensitivity under water falls of fat about 16 dB/octave to reach an average loss of about 30 dB above 0.4 kHz. In terms of SIL, the organism is about 30 dB more sensitive under water than in air below 0.2 kHz and equally sensitive in air and water above 0.4 kHz.The relative merits of the two measures are discussed and an attempt is made to relate the results to morphology of the middle and inner ears. This report is the first to compare aerial and underwater hearing abilities in any organism using electrode implants.

Acoustic Parts in Vehicle Sound Transmission Loss Test Method Research

2013 ◽  
Vol 380-384 ◽  
pp. 73-76
Author(s):  
Xiu Feng Wang ◽  
Jie Shi
Keyword(s):  
Sound Pressure ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Intensity ◽  
Pressure Level ◽  
Test Method ◽  
Intensity Level ◽  
Sound Transmission Loss ◽  
Passenger Compartment ◽  
Exterior Panel

The sound transmission loss (STL) of the acoustic parts in the vehicle was proposed to be computed using the Sound Pressure Level measured at the several locations inside the vehicle and the transmitted Sound Intensity Level on the vehicles exterior panel, which the acoustic treated vehicle passenger compartment is assumed as a small reverberation room. The necessary parts retrofits and acoustic treatments for Sound transmission loss tests of the acoustic parts in the vehicle were listed. The values of the appropriate number and positions of the loud speakers, microphones and sound intensity probes for Sound transmission loss of the acoustic parts in the vehicle were recommended. The in vehicle sound transmission loss tests of the acoustic parts such as the doors, carpets, wheel house etc. were achieved in the semi-anechoic room. Based on the door system, the correlation work has been done among the methods of the proposed in vehicle STL test, the reverberation - semi-anechoic chamber buck STL test and SEA analysis.

scholarly journals Protective effect of Nigella sativa oil on acoustic trauma induced hearing loss in rats

2017 ◽  
Vol 7 (2) ◽  
Author(s):  
Belde Culhaoglu ◽  
Selim S. Erbek ◽  
Seyra Erbek ◽  
Evren Hizal
Keyword(s):  
Hearing Loss ◽  
Protective Effect ◽  
Nigella Sativa ◽  
Acoustic Trauma ◽  
Female Rats ◽  
Auditory Brainstem Responses ◽  
Control Group ◽  
Study Group ◽  
Intensity Level ◽  
Hearing Thresholds

Acoustic trauma is a common reason for hearing loss. Different agents are used to prevent the harmful effect of acoustic trauma on hearing. The aim of this study was to evaluate the potential preventive effect of <em>Nigella sativa</em> (black cumin) oil in acoustic trauma. Our experimental study was conducted with 20 Sprague Downey female rats (mean age, 12 months; mean weight 250 g). All of the procedures were held under general anesthesia. Following otoscopic examinations, baseline-hearing thresholds were obtained using auditory brainstem responses (ABR). To create acoustic trauma, the rats were then exposed to white band noise of 4 kHz with an intensity level of 107 dB in a soundproof testing room. On Day 1 following acoustic trauma, hearing threshold measurements were repeated. The rats were divided into two groups as the study group (n: 10) and the controls (n: 10). 2 mL/kg/day of <em>Nigella sativa</em> oil was given to the rats in the study group orally. On Day 4 following acoustic trauma, ABR measurements were repeated again. There was no difference between the baseline hearing thresholds of the rats before acoustic trauma (P&gt;0.005). After the acoustic trauma, hearing thresholds were increased and there was no significant statistically difference between the hearing thresholds of the study and control groups (P=0.979). At the 4<sup>th</sup> day following acoustic trauma, hearing thresholds of the rats in control group were found to be higher than those in the study group (P=0.03). Our results suggest that <em>Nigella sativa</em> oil has a protective effect against acoustic trauma in early period. This finding should be supported with additional experimental and clinical studies, especially to determine the optimal dose, duration and frequency of potential <em>Nigella sativa</em> oil therapy.

Research on the Ventilator Noise Sound Intensity Measure

2013 ◽  
Vol 765-767 ◽  
pp. 2113-2116
Author(s):  
Rong Jie Wang ◽  
Hong Wei Chen
Keyword(s):  
Density Function ◽  
Sound Pressure ◽  
Sound Intensity ◽  
Vibration Velocity ◽  
Velocity Spectrum ◽  
Practical Application ◽  
Intensity Measure ◽  
Spectrum Density ◽  
Important Means ◽  
Gradient Change

Noise measurement is the important means on the noise monitoring, evaluation and control.At present the error of sound pressure method widely used is larger. It adopts the method of double microphone in the method of sound intensity measurement,and uses acoustic pressure gradient change to approximately equal the particle vibration velocity, spectrum density function is obtained by using sound intensity analyzer,it computes integral for Spectrum density function that are sound intensity.In this paper, by measuring sound intensity of ventilator and comparing the numerical results and experimental results, it confirmed that the method is high precision, has practical application value.

The Study of Method for Calculating Geometric Average Sound Intensity in Scattering Field

2010 ◽  
Vol 458 ◽  
pp. 185-191
Author(s):  
Feng Li Luo ◽  
Guang Yu Li
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Computing Time ◽  
Sound Intensity ◽  
Frequency Range ◽  
Average Value ◽  
Geometric Average ◽  
Scattering Field ◽  
Measurement Efficiency ◽  
Frequency Area

When calculating sound intensity by indirectly measuring way, the sound pressures obtained from two microphones should be mathematically averaged as the sound pressure of measured point. The research showed that the method exists lower of allowable value in the high frequency area. Using the geometric average value of two measured points to replace the sound pressure of measured point, studying the measurement of sound intensity in scattering field, the errors from which were compared. The result showed that the error of geometric average sound intensity was more flat than that of mathematic average. So the sound intensity obtained from geometric average sound pressure is more suitable for the measurement of a wider frequency range. And the computing time is short, which can raise the measurement efficiency and the real-time of measurement.

An analysis of the mechanics of phonation

1965 ◽  
Vol 20 (2) ◽  
pp. 301-307 ◽  
Author(s):  
G. A. Cavagna ◽  
R. Margaria
Keyword(s):  
Sound Production ◽  
Respiratory Muscles ◽  
Sound Intensity ◽  
Sound Level ◽  
Intensity Level ◽  
Elastic Recoil ◽  
Mechanical Models ◽  
Fine Regulation ◽  
Flow Through ◽  
Work Done

The mechanical work done by the chest in phonation has been measured together with the sound intensity level. The regulation of the sound intensity is done by regulating the intrapulmonary pressure. This is achieved at high intensity levels through the activity of the respiratory muscles that, together with the elastic recoil of the chest, sustain the work of phonation. At sound intensities below a critical level an additional mechanism for changing the intensity is given by a fine regulation of the opening of the glottis, thus allowing more air to escape without contributing to sound production. The contribution of the respiratory muscles, of the chest elasticity, and of the opening of the glottis to phonation at different intensity levels depend on the degree of inflation of the chest. The efficiency of phonation, as of sound production in mechanical models, seems to increase with increasing intensity and pitch. voice production; work done by chest during phonation; mechanical models of glottis generator; subglottic pressure as a function of sound level; air flow through glottis during phonation; efficiency changes of sound production; variation of sound intensity by regulating opening of glottis; variations of the area of glottis depending on extent of elastic recoil of chest Submitted on February 10, 1964

Measurement of the sound intensity during suction of middle-ear fluid following myringotomy

2014 ◽  
Vol 128 (7) ◽  
pp. 604-611 ◽  
Author(s):  
J C Wang ◽  
S J Allen ◽  
A I Rodriguez ◽  
C Zahner ◽  
S Dissanaike ◽  
...  
Keyword(s):  
Middle Ear ◽  
Sound Pressure ◽  
Prospective Observational Study ◽  
Sound Intensity ◽  
Frequency Domain Analysis ◽  
Serous Effusion ◽  
Noise Levels ◽  
Middle Ear Fluid ◽  
Significant Difference ◽  
Ear Effusion

AbstractObjective:To determine noise intensity during middle-ear aspiration in order to evaluate whether levels can be potentially harmful.Methods:In this prospective, observational study, middle-ear effusion was aspirated following myringotomy using a suction instrument with a probe tube microphone. Sound pressure levels and duration were measured, and frequency domain analysis was performed.Results:Forty-four ears were analysed, consisting of 20 with mucoid effusion, 11 with serous effusion and 13 with no effusion. Maximum peak sound intensity ranged from 84 to 157 dB. Half of the ears (50 per cent) were exposed to greater than 140 dB; of these, 82 per cent were exposed for longer than 0.2 ms (range, 0.05–14 ms). There was no significant difference in sound pressure level between ears with mucoid and serous effusion; however, ears with mucoid effusion required longer suction times (p < 0.0030). In addition, peak intensity was greater for ears with mucoid effusion versus those with serous or no effusion (p < 0.0001).Conclusion:Middle-ear aspiration during myringotomy caused noise levels within a potentially harmful range.

Unraveling the Mystery of Auditory Brainstem Response Corrections: The Need for Universal Standards

2017 ◽  
Vol 28 (10) ◽  
pp. 950-960 ◽  
Author(s):  
Linda W. Norrix ◽  
David Velenovsky
Keyword(s):  
Auditory Brainstem Response ◽  
Auditory Brainstem ◽  
Evidence Based ◽  
Test Results ◽  
Behavioral Thresholds ◽  
Hearing Thresholds ◽  
Brainstem Response ◽  
Two Measures ◽  
Impaired Children ◽  
Universal Standard

Background: The auditory brainstem response (ABR) is used to estimate behavioral hearing thresholds in infants and difficult-to-test populations. Differences between the toneburst ABR and behavioral thresholds exist making the correspondence between the two measures less than perfect. Some authors have suggested that corrections be applied to ABR thresholds to account for these differences. However, because there is no agreed upon universal standard, confusion regarding the use of corrections exists. Purpose: The primary purpose of this article is to review the reasoning behind and use of corrections when the toneburst ABR is employed to estimate behavioral hearing thresholds. We also discuss other considerations that all audiologists should be aware of when obtaining and reporting ABR test results. Results: A review of the purpose and use of corrections reveals no consensus as to whether they should be applied or which should be used. Additionally, when ABR results are adjusted, there is no agreement as to whether additional corrections for hearing loss or the age of the client are necessary. This lack of consensus can be confusing for all individuals working with hearing-impaired children and their families. Conclusions: Toneburst ABR thresholds do not perfectly align with behavioral hearing thresholds. Universal protocols for the use of corrections are needed. Additionally, evidence-based procedures must be employed to obtain valid ABRs that will accurately estimate hearing thresholds.

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