Some observations on the masking and post-masking effects of tinnitus

1984 ◽  
Vol 98 (S9) ◽  
pp. 150-156 ◽  
Author(s):  
Richard S. Tyler ◽  
Richard W. Babin ◽  
Diane P. Niebuhr
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Broadband Noise ◽  
Minimum Level ◽  
Sensation Level ◽  
Masker Level ◽  
Different Types ◽  
Masker Duration ◽  
Percep Tion

AbstractThe symptom of tinnitus is likely shared by several underlying pathologies. It is funda-mental to the investigation and treatment of tinnitus to be able to reliably quantify different types of tinnitus. In one experi-ment we required patients to increase the level of a broadband noise until it just masked their tinnitus. Regardless of where in the head they perceive their tinnitus, in most patients the minimum level (in sound pressure level or sensation level) required to mask the tinnitus is similar in both ears. In a few other patients, the tinnitus cannot be masked or requires high levels in the contra-lateral ear. We have found this masking procedure valuable in measuring tinnitus following the administration of tocainide. In some patients the tocainide seemed to reduce the magnitude of the tinnitus (required lower masker levels to mask the tinnitus) whereas in others there was some evidence that the tinnitus got worse (higher masker levels were required). In another experiment, we quantified tinnitus percep-tion following the termination of a masker. Several different patterns were evident. After the termination of the masker, the tinnitus either (a) returned to normal immediately, (b) returned immediately but was at a softer loudness, (c) was absent for a time before gradually returning to normal, (d) was absent for a time before abruptly returning to normal, or (e) was louder than normal before gradually returning to normal. Increasing masker duration and masker level prolonged the effects.

Investigation of Cavitation Phenomena on Noise of Underwater Propeller

2017 ◽  
Author(s):  
Amir Karimi Noughabi ◽  
Morteza Bayati ◽  
Mehran Tadjfar
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Control Strategies ◽  
Noise Analysis ◽  
Pressure Level ◽  
Broadband Noise ◽  
Marine Propeller ◽  
Cavitation Noise ◽  
Radiated Noise ◽  
Thrust And Torque

Underwater propeller cavitation noise is composed of tonal blade rate noise and high frequency broadband noise. Cavitation usually increases overall sound pressure level in the various frequency ranges which depends on the type of cavitation. This research had been carry out to predict the radiated noise from a marine propeller in presence of cavitation with various cavitation types. The analysis is performed by coupling an acoustic code based on the Ffowcs Williams-Hawkings (FWH) equation to unsteady Reynolds-averaged Navier-Stokes (URANS) which able to simulate multiphase flows in rotational domains. A brief summary of numerical method used to model the cavitation around the underwater propeller are presented and the thrust and torque coefficients are validated in different flow conditions by experimental results. The radiated noise along the shaft direction and perpendicular to the shaft direction is studied on both cavitating and non-cavitating propellers. Then, to predict the radiated noise due to cavitation in marine propeller, the computed sound pressure level (SPL) for non-cavitating marine propeller is compared with the SPL for the same propeller in cavitation conditions at various cavitation number and advanced coefficients. The noise analysis helps to determine the dominant noise source of the underwater propeller in different conditions, which will provide a basis for proper noise control strategies.

Suprathreshold Auditory Adaptation in Normal and Pathologic Ears

1968 ◽  
Vol 11 (2) ◽  
pp. 268-278 ◽  
Author(s):  
Fred Harbert ◽  
Betty Goldman Weiss ◽  
Chester R. Wilpizeski
Keyword(s):  
Sound Pressure Level ◽  
Clinical Setting ◽  
Sound Pressure ◽  
Diagnostic Information ◽  
Pressure Level ◽  
Balance Method ◽  
Sensation Level ◽  
Frequency Sound ◽  
Auditory Adaptation ◽  
Consistent Relationship

The Wood delayed loudness balance method was studied in normal and pathologic ears to determine the characteristics of suprathreshold auditory adaptation in three groups of subjects. No consistent relationship could be established between the amount and direction of the loudness change with the frequency, sound pressure level, or sensation level of the adapting signal. Suprathreshold adaptation, as measured by the Wood method, does not provide sufficient diagnostic information to be useful in a clinical setting.

Study on acoustic environment of canteens in South China University of Technology

2021 ◽  
Vol 263 (5) ◽  
pp. 1695-1702
Author(s):  
Ziyu Zhou ◽  
Hongwei Wang
Keyword(s):  
South China ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Noise Sources ◽  
Acoustic Environment ◽  
University Of Technology ◽  
Different Types ◽  
Satisfaction Evaluation ◽  
The Voice

In order to understand the characteristics of the acoustic environment of University canteens, the canteens of South China University of Technology were selected as the research objects, and the acoustic parameters were measured on the spot and the questionnaire survey was conducted. The results show that the average sound pressure level of restaurants with smaller area is lower than that of restaurants with larger area, and the sound pressure level of dining space first increases rapidly, then increases slowly, and finally remains unchanged with the increase of the number of diners. In the aspect of restaurant acoustic environment satisfaction evaluation, the space with the smallest dining area has the highest acoustic environment satisfaction evaluation level, and the collision sound of tableware collection and table and chair moving has the highest correlation with the acoustic environment satisfaction evaluation. In terms of different types of noise sources, diners think that the most disturbing noise for conversation is the voice of the surrounding people, followed by the collision of tables and chairs and the collection of tableware, and the least disturbing noise is the noise of air conditioning and kitchen equipment.

scholarly journals Noise Emissions in Milking Parlours with Various Construction Solutions

2016 ◽  
Vol 19 (2) ◽  
pp. 49-51
Author(s):  
Marie Šístková ◽  
Martin Pšenka ◽  
Ivo Celjak ◽  
Petr Bartoš ◽  
Štefan Mihina ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Noise Exposure ◽  
Pressure Level ◽  
Different Types ◽  
Sound Pressure Levels ◽  
Mechanical Devices

Abstract Mechanical devices in parlours are a source of noise, and this noise has an effect not only on the operators of the parlour but also on dairy cows. They have more sensitive hearing than humans. The aim of this article was to analyse the sound pressure level and determine the noise exposure of dairy cows at different technological solutions of milking parlours, during their day routine. In the experiment, tandem, herringbone and rotary milking parlours were used. Noise exposure was measured during the milking process. After evaluation of noise pressure levels of different types of milking parlours, it can be concluded that in this experiment, the equivalent noise pressure level was lowest in the tandem milking parlour. Equivalent sound pressure levels in the rotary and herringbone milking parlour were almost about the same values. These values are higher than values in the tandem milking parlour, about 10 decibels. The differences within mean LAFeq values between the herringbone milking parlour and tandem milking parlour were highly statistically significant (P <0.001***).

The comparative effects of signal sensation level and sound‐pressure level on interaural time discrimination

1985 ◽  
Vol 78 (3) ◽  
pp. 908-915 ◽  
Author(s):  
Marion F. Cohen ◽  
Janet Koehnke ◽  
Anne E. McClave ◽  
Patricia Gregorio Pallanck
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Sensation Level ◽  
Time Discrimination

scholarly journals The assessment of the sawmill noise

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
P. D’Antonio ◽  
C. D’Antonio ◽  
C. Evangelista ◽  
V. Doddato
Keyword(s):  
Data Processing ◽  
Sound Pressure Level ◽  
Noise Level ◽  
Sound Pressure ◽  
Sound Level ◽  
Pressure Level ◽  
Published Data ◽  
Noise Levels ◽  
Different Types ◽  
Level Meter

Noise is a serious and widespread problem in many workplaces like in sawmill. The published data for the year 2010 about the total number of pathologies from work in Italia due to the noise, showed 5222 cases divided by sex, in fact for females there are instances in number of 221 while the male has a number of cases is equal to 4961. The aim of this work was to detect the sound level caused by the use of the machineries in a sawmill. The measurements were carried out through an instrument known as noise level meter, equipped with a microphone and connected to a computer for data processing and analysis of variance to a factor in excel, and able to assess noise levels at any particular point in the mill. The machines were subjected in relief and with several different types of wood materials. Obviously, in our case a fundamental role takes the moisture of wood. The drying operation is intended to obtain that degree of humidity of the wood, generally it must be between 7 and 16%, compatible with the type of glue used and, above all, appropriate to the target structures. The machines that have the highest sound pressure levels were trimmer and profiler, with values ranging between 85 dB(A) and 110 dB(A). Finally, it’s possible conclude that the sound pressure level increases when the aspiration equipment is turned on, the noise of machinery decreases during the processing of wood and that, increasing the thickness, decreased the noise emitted by the machine.

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