The Effect of Altitude on Absolute Hearing Threshold Levels

1982 ◽  
Vol 26 (5) ◽  
pp. 488-492
Author(s):  
I. B. Mekjavic ◽  
D. Sinclair ◽  
D. Steele ◽  
N. S. Longridge
Keyword(s):  
Ambient Pressure ◽  
Hearing Threshold ◽  
Experimental Conditions ◽  
Exposure Test ◽  
Threshold Levels ◽  
Hearing Thresholds ◽  
Insignificant Difference ◽  
The Mean ◽  
Pure Tones ◽  
The One

The present study investigates the effect of hypobaric environments on absolute hearing thresholds for pure tones at octave frequencies between 250 Hz and 8 kHz. Absolute hearing thresholds were obtained for ten subjects at ambient pressure (732 mmHg) and at an altitude of 6500 feet (582 mmHg), relative to the laboratory. Subjects were decompressed in a hypobaric chamber at a rate of 500 ft./min. and were subjected to the low pressure environment for one hour before being compressed to a normobaric environment, at a rate of 300 ft./min. Absolute hearing threshold levels obtained at altitude, after the one hour exposure to the hypobaric ambient and on descent to normobaric conditions, were compared with scores obtained prior to the hypobaric exposure. In order to compare the frequency averaged threshold shifts at octave frequencies of 250 Hz, 500 Hz and 1 kHz, for the altitude and normobaric conditions, the audiometer was calibrated at ambient pressures of 732, 582 and 512 mmHg. The results of the study indicate a slight increase in sensitivity of the audiometer headphones with altitude and an insignificant difference between the mean frequency averaged threshold shifts for the pre-exposure test and the three experimental conditions (at the onset of hypobaria, after a one hour exposure to the altitude and on descent to surface).

scholarly journals Effect of age and duration of driving on hearing status of Indian agricultural tractor drivers

2018 ◽  
Vol 37 (4) ◽  
pp. 1037-1044
Author(s):  
Abhijit Khadatkar ◽  
CR Mehta
Keyword(s):  
Hearing Impairment ◽  
Hearing Threshold ◽  
Office Workers ◽  
Age Group ◽  
Driving Experience ◽  
Threshold Levels ◽  
Increase With Increase ◽  
The Mean ◽  
Audiometric Test ◽  
Effect Of Age

Tractor noise is critical occupational hazard which is the major cause of hearing impairment among Indian agricultural farm workers. The study aimed to show the effect of age and driving exposure on hearing impairment of drivers. Ninety healthy male subjects of similar age, height, and weight were selected and divided into four groups, i.e. 21–30, 31–40, 41–50, and 51–60 years. The audiometric testing was conducted of both the ears at 10 different frequencies, i.e. 0.125, 0.25, 0.5, 1, 1.5, 2, 3, 4, 6, and 8 kHz. The hearing threshold levels of office workers at audiometric test frequencies did not exceed 25 dB(A) to cause hearing handicap. However, it exceeded 25 dB(A) for tractor drivers and was higher for higher age group tractor drivers. Whereas, it did not exceeded 25 dB(A) at the audiometric test frequencies for the office workers except at 51–60 years of age group. Also, with the increase in age group and increase of driving experience, the mean hearing threshold levels of tractor drivers increase. It was concluded that the occupational hazards of tractor driving significantly increased the hearing threshold levels and the risk is even higher for the tractor drivers with ≥15 years of driving experience. Also, the mean hearing threshold levels for tractor drivers increase with increase in driving experience.

scholarly journals Variation in the Hearing Threshold in Women during the Menstrual Cycle

2017 ◽  
Vol 21 (04) ◽  
pp. 323-328 ◽  
Author(s):  
Dayse Souza ◽  
Brunna Luckwu ◽  
Wagner Andrade ◽  
Luciane Pessoa ◽  
João Nascimento ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Hearing Threshold ◽  
Hormonal Contraceptives ◽  
Control Group ◽  
Hormonal Changes ◽  
High Frequencies ◽  
Hearing Thresholds ◽  
Hormonal Fluctuations ◽  
The Mean ◽  
Late Follicular Phase

Introduction The hormonal changes that occur during the menstrual cycle and their relationship with hearing problems have been studied. However, they have not been well explained. Objective The objective of our study is to investigate the variation in hearing thresholds in women during the menstrual cycle. Method We conducted a cohort and longitudinal study. It was composed of 30 volunteers, aged 18–39 years old, of which 20 were women during the phases of the menstrual cycle and 10 were men (control group) who underwent audiometry and impedance exams, to correlate the possible audiological changes in each phase of the menstrual cycle. Results There were significant changes in hearing thresholds observed during the menstrual cycle phases in the group of women who used hormonal contraceptives and the group who did not use such contraceptives. Improved hearing thresholds were observed in the late follicular phase in the group who did not use hormonal contraceptives and the hearing thresholds at high frequencies were better. Throughout the menstrual cycle phases, the mean variation was 3.6 db HL between weeks in the group who used hormonal contraceptives and 4.09 db HL in the group who did not use them. Conclusions The present study found that there may be a relationship between hearing changes and hormonal fluctuations during the menstrual cycle based on changes in the hearing thresholds of women. In addition, this study suggests that estrogen has an otoprotective effect on hearing, since the best hearing thresholds were found when estrogen was at its maximum peak.

AN OBSERVATIONAL STUDY OF HEARING THRESHOLDS IN PROFESSIONAL DRIVERS

2021 ◽  
pp. 49-51
Author(s):  
R. Shanthimalar ◽  
R. Bhuvaneswari ◽  
V. Sumathi
Keyword(s):  
Hearing Loss ◽  
Tamil Nadu ◽  
Pure Tone ◽  
Hearing Threshold ◽  
Pure Tone Audiometry ◽  
P Value ◽  
Professional Drivers ◽  
Threshold Levels ◽  
Hearing Thresholds ◽  
The Right

Introduction: Noise has become a very important stress factor in the environment. Drivers are the most commonly affected persons due to trafc noise. The majority of drivers remain unaware about noise induced hearing loss as this is an insidious process, leading to temporary or permanent hearing impairment, but preventable. Pure Tone audiometric test is used to determine the degree of hearing loss in noise exposed individuals. Aim & Objective: To nd the hearing threshold levels for high and mid frequency sounds for both ears in Professional drivers. To evaluate the preponderance of hearing loss between right and left ear using hearing thresholds. Materials & Methods: This study was conducted in 100 Professional male drivers aged between 30-40 years who are working in Tamil Nadu State Transport Corporation, Madurai. Pure tone audiometry was used to measure the high and mid frequency hearing threshold levels in both ears. Results: The mean (SD) hearing threshold for high and mid frequency sounds was signicantly higher in left ear comparative to right ear with P value < 0.05. The statistically signicant difference in hearing loss was observed between both ears. Conclusion : Our study showed statistically signicant higher hearing threshold for high and mid frequency sounds in left ear compared to right ear, that concludes left ear is more prone for hearing loss than the right ear

A Cross-Sectional Study on the Hearing Threshold Levels Among People in Qinling, Qinghai, and Nanjing, China

2018 ◽  
Vol 27 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Junguo Wang ◽  
Xiaoyun Qian ◽  
Jie Chen ◽  
Ye Yang ◽  
Xia Gao
Keyword(s):  
Age Groups ◽  
Hearing Threshold ◽  
Sampling Technique ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Systematic Random Sampling ◽  
Auditory Thresholds ◽  
Threshold Levels ◽  
Hearing Ability ◽  
Hearing Thresholds

Purpose This study aimed to investigate the hearing threshold among different age groups, genders, and geographic areas in China to provide some insight into the appropriate clinical interventions for hearing loss. Method Using a systematic random sampling technique, 562 participants from Qinling, Qinghai, and Nanjing were included. Participants in the same area were divided into 3 groups according to their age. Pure-tone audiometric thresholds were measured at octave and interoctave frequencies of 0.125–16 kHz for each subject. Results There were significant differences in auditory thresholds at nearly all frequencies among young, middle-aged, and elderly people, and hearing thresholds increased with increasing age. People generally had the best hearing ability in Nanjing, better hearing ability in Qinghai, and the worst hearing ability in Qinling. Significant differences in hearing thresholds were found between males and females at several frequencies in Qinling. Conclusion People living in the rural area of Qinling in China had higher hearing threshold levels, particularly males, and hearing thresholds increased with age.

scholarly journals Temporal resolution with click and pure tone stimuli in youngsters with normal hearing sensitivity

2012 ◽  
Vol 24 (2) ◽  
pp. 168-173 ◽  
Author(s):  
Luciana Leal de Sousa ◽  
Karin Ziliotto Dias ◽  
Liliane Desgualdo Pereira
Keyword(s):  
Temporal Resolution ◽  
Auditory Stimulus ◽  
Pure Tone ◽  
Normal Hearing ◽  
Gap Detection ◽  
Temporal Acuity ◽  
Hearing Sensitivity ◽  
Hearing Thresholds ◽  
The Mean ◽  
Pure Tones

PURPOSE: To assess the auditory ability of temporal resolution and to compare the random gap detection test (RGDT) versions with pure tone and clicks stimuli. METHODS: Participants were 40 young individuals of both genders with ages between 18 and 25 years, and normal hearing thresholds for the sound frequencies of 250 Hz to 8 kHz. Initially, participants were submitted to the basic audiological evaluation. Then they underwent the RGDT with pure tone and clicks stimuli. Finally, we obtained the temporal acuity threshold, which corresponds to the shorter silence interval in which the patient perceives two sounds, for each type of stimulus, called final temporal acuity threshold for pure tones (mean of the thresholds obtained for 500 Hz, 1k, 2k and 4 kHz), and temporal acuity threshold for clicks. RESULTS: The mean temporal acuity threshold for the sound frequency of 500 Hz was 7.25 ms; for the frequency of 1 kHz was 7.25 ms; for 2 kHz was 6.73 ms; for the frequency of 4 kHz was 6.03 ms. The final temporal acuity threshold was 6.72 ms. The mean temporal acuity threshold for clicks was 6.43 ms. No difference was found between the temporal acuity thresholds obtained with pure tone and clicks stimuli. CONCLUSION: There is no difference in the performance of individuals on the auditory ability of temporal resolution, regardless of the auditory stimulus used.

scholarly journals Reversible Audiometric Threshold Changes in Children with Uncomplicated Malaria

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
George O. Adjei ◽  
Bamenla Q. Goka ◽  
Emmanuel Kitcher ◽  
Onike P. Rodrigues ◽  
Ebenezer Badoe ◽  
...  
Keyword(s):  
Uncomplicated Malaria ◽  
Hearing Threshold ◽  
Antimalarial Drugs ◽  
Acute Illness ◽  
Acute Stage ◽  
Control Group ◽  
Learning And Development ◽  
Threshold Levels ◽  
Hearing Thresholds ◽  
Artemisinin Combination Therapies

Background.Plasmodium falciparummalaria, as well as certain antimalarial drugs, is associated with hearing impairment in adults. There is little information, however, on the extent, if any, of this effect in children, and the evidence linking artemisinin combination therapies (ACTs) with hearing is inconclusive.Methods. Audiometry was conducted in children with uncomplicated malaria treated with artesunate-amodiaquine (n=37), artemether-lumefantrine (n=35), or amodiaquine (n=8) in Accra, Ghana. Audiometry was repeated 3, 7, and 28 days later and after 9 months. Audiometric thresholds were compared with those of a control group of children (n=57) from the same area.Findings. During the acute stage, hearing threshold levels of treated children were significantly elevated compared with controls (P<0.001). The threshold elevations persisted up to 28 days, but no differences in hearing thresholds were evident between treated children and controls after 9 months. The hearing thresholds of children treated with the two ACT regimens were comparable but lower than those of amodiaquine-treated children during acute illness.Interpretation. Malaria is the likely cause of the elevated hearing threshold levels during the acute illness, a finding that has implications for learning and development in areas of intense transmission, as well as for evaluating potential ototoxicity of new antimalarial drugs.

scholarly journals A study of the high-frequency hearing thresholds of dentistry professionals

2012 ◽  
Vol 16 (02) ◽  
pp. 226-231 ◽  
Author(s):  
Ana de Melo ◽  
Cibele Santos ◽  
Andréa Lopes
Keyword(s):  
High Frequency ◽  
Hearing Threshold ◽  
Impaired Hearing ◽  
Prevention Measures ◽  
Hearing Ability ◽  
Group I ◽  
Hearing Thresholds ◽  
High Frequency Audiometry ◽  
The Mean ◽  
Frequency Threshold

Summary Introduction: In the dentistry practice, dentists are exposed to harmful effects caused by several factors, such as the noise produced by their work instruments. In 1959, the American Dental Association recommended periodical hearing assessments and the use of ear protectors. Aquiring more information regarding dentists', dental nurses', and prosthodontists' hearing abilities is necessary to propose prevention measures and early treatment strategies. Objective: To investigate the auditory thresholds of dentists, dental nurses, and prosthodontists. Method: In this clinical and experimental study, 44 dentists (Group I; GI), 36 dental nurses (Group II; GII), and 28 prosthodontists (Group III; GIII) were included, , with a total of 108 professionals. The procedures that were performed included a specific interview, ear canal inspection, conventional and high-frequency threshold audiometry, a speech reception threshold test, and an acoustic impedance test. Results: In the 3 groups that were tested, the comparison between the mean hearing thresholds provided evidence of worsened hearing ability relative to the increase in frequency. For the tritonal mean at 500 to 2,000 Hz and 3,000 to 6,000 Hz, GIII presented the worst thresholds. For the mean of the high frequencies (9,000 and 16,000 Hz), GII presented the worst thresholds. Conclusion: The conventional hearing threshold evaluation did not demonstrate alterations in the 3 groups that were tested; however, the complementary tests such as high-frequency audiometry provided greater efficacy in the early detection of hearing problems, since this population's hearing loss impaired hearing ability at frequencies that are not tested by the conventional tests. Therefore, we emphasize the need of utilizing high-frequency threshold audiometry in the hearing assessment routine in combination with other audiological tests.

Articulatory Behavior Pre and Post Full-Mouth Tooth Extraction and Alveoloplasty

1980 ◽  
Vol 23 (3) ◽  
pp. 630-645 ◽  
Author(s):  
Gerald Zimmermann ◽  
J.A. Scott Kelso ◽  
Larry Lander
Keyword(s):  
Control Subject ◽  
High Speed ◽  
Tooth Extraction ◽  
Kinematic Parameters ◽  
Experimental Conditions ◽  
Mean Values ◽  
Articulatory Movements ◽  
The Mean ◽  
Experimental Subjects ◽  
Normal Speech

High speed cinefluorography was used to track articulatory movements preceding and following full-mouth tooth extraction and alveoloplasty in two subjects. Films also were made of a control subject on two separate days. The purpose of the study was to determine the effects of dramatically altering the structural dimensions of the oral cavity on the kinematic parameters of speech. The results showed that the experimental subjects performed differently pre and postoperatively though the changes were in different directions for the two subjects. Differences in both means and variabilities of kinematic parameters were larger between days for the experimental (operated) subjects than for the control subject. The results for the Control subject also showed significant differences in the mean values of kinematic variables between days though these day-to-day differences could not account for the effects found pre- and postoperatively. The results of the kinematic analysis, particularly the finding that transition time was most stable over the experimental conditions for the operated subjects, are used to speculate about the coordination of normal speech.

The effect of altitude on absolute hearing threshold levels

1982 ◽  
Author(s):  
I. B. Mekjavic ◽  
D. Sinclair ◽  
D. Steele ◽  
N. S. Longridge
Keyword(s):  
Hearing Threshold ◽  
Threshold Levels
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