Hearing status among commercial pilots in a Swedish airline company

Do Flights Affect Hearing in Hot Air Balloon Pilots?

PURPOSE

This study aimed to reveal occupational effects on the hearing of hot air balloon (HAB) pilots and examine the relationship between the duration of experience and these effects.

METHOD

This study included 31 male HAB pilots and a control group of 32 male participants. Tympanometry, eustachian tube function (ETF) test, pure-tone audiometry, and transient evoked otoacoustic emission (TEOAE) tests were performed.

RESULTS

Pure-tone audiometry results were significantly worse at 125, 500, and 6000 Hz in the right ear and 125, 500, 4000, and 6000 Hz in the left ear in the HAB group than the control group. Although tympanometry evaluation parameters did not differ between the HAB and control groups, ETF test was significantly worse in the HAB group than the controls bilaterally. TEOAE results were significantly worse at 1000, 2000, and 4000 Hz in the right ear and 4000 Hz in the left ear in the HAB group than the controls. There was a significant positive correlation for 125, 4000, 6000, and 8000 Hz between the duration of experience and right ear hearing thresholds. For the left ear, the duration of experience showed a significant positive correlation at 3000, 4000, 6000, and 8000 Hz. When the relationship between the duration of experience and TEOAE results was evaluated, a significant negative correlation was found at 4000 Hz in the left ear.

CONCLUSION

In HAB pilots, in whom eustachian tube dysfunction is quite common, noise and high altitude affected hearing, especially low and high frequencies, and the duration of experience was found to be associated with hearing thresholds.

Separated and coupled effects of illumination, accumulated noise and task complexity on cognitive-motor performance dynamics

BACKGROUND: Inconsistent findings on coupled illumination, accumulated noise and task complexity effects on cognitive-motor performance asked for a more comprehensive analysis by focusing on performance dynamics. OBJECTIVE: The aim was to investigate the effects of illumination, accumulated noise, and task complexity on several average and non-average temporal indicators. METHODS: The research was designed as a mixed factorial quasi-experiment including 83 students of transport (n = 42) and psychology (n = 41) at the University of Zagreb. Participants were assigned to designated experimental conditions defined by illumination (40, 280, 3400 lx), and accumulated noise (0% and 50% of the daily exposure limit) levels and all performed 2- and 8-choice reaction time tests. RESULTS: The findings showed negative effects of accumulated noise and task complexity on all performance indicators, while the effect of illumination reached significance only for maximal speed. Significant Illumination x Task complexity and Illumination x Accumulated noise effects were obtained for average efficiency, while significant Accumulated noise x Task complexity effect was observed for average efficiency and maximal speed. CONCLUSIONS: Various indicators of performance dynamics were diversely affected by external factors, thereby suggesting the effects’ mechanisms, and accentuating different guidelines for design of workplaces that include these environmental stressors.

Are the hearing and eustachian tube functions of the hot air balloon pilots disturbed?

OBJECTIVE

To evaluate the hearing and Eustachian tube functions (ETF) of hot air balloon (HAB) pilots, who are exposed to high altitude occupationally.

MATERIALS AND METHODS

The study was designed as a cross-sectional controlled study. Thirty HAB pilots and 30 healthy volunteers were included. Pure tone audiometry and speech discrimination scores (SDS) were used to assess the hearing function. Pure tone average (PTA) was calculated using the hearing thresholds (HT) at the frequencies 500, 1000, 2000, and 4000 Hz. Tympanometry and automatic Williams test (ETF1) were conducted to assess the ETF of the participants. Eustachian Tube Dysfunction (ETD) was defined as the change of tympanometric peak pressure (TPP) at rest (P1) less than in 10 decapascals (daPa) with Valsalva (P2) and Toynbee (P3) maneuvers. Eustachian Tube Dysfunction Questionnaire-7 (ETDQ-7) was also administrated.

RESULTS

Mean ages of the participants were 32.03±8.12 and 32.33±9.47 years in the HAB and control groups, respectively (p = 0.865). HTs, PTAs, SDSs, P1, P2, P2-P1 and P1-P3 values were similar in the groups (p > 0.05). P3 values ​​in both ears were significantly higher in the HAB group compared to the control group (p = 0.018, p = 0.002). Positive correlations were detected between the duration of the experience of HAB pilots and their HTs at 4 kHz and 8 kHz (p < 0.05) The prevalence of ETD in at least one ear was 83.7% and in both ears was 43.3% in the HAB group, both of which were significantly higher than the control group (p = 0.001, p = 0.049). The ETDQ-7 scores were also higher in the HAB group compared to the control group (p < 0.001).

CONCLUSION

Both the subjective and objective measures of ETF indicate that ETD is common among the HAB pilots. However, the hearing functions of those seem to be unaffected.

Hearing threshold shifts among military pilots of the Israeli Air Force

Background

Military aviators are potentially at risk for developing noise-induced hearing loss. Whether ambient aircraft noise exposure causes hearing deficit beyond the changes attributed to natural ageing is debated. The aim of this research was to assess changes in hearing thresholds of Israeli Air Force (IAF) pilots over 20 years of military service and identify potential risk factors for hearing loss.

Methods

A retrospective cohort analysis was conducted of pure-tone air conduction audiograms of pilots, from their recruitment at 18 years of age until the last documented medical check-up. Mean hearing thresholds were analysed in relation to age, total flight hours and aircraft platform. Comparisons were made to the hearing thresholds of air traffic controllers (ATCs) who were not exposed to the noise generated by aircraft while on duty.

Results

One hundred and sixty-three pilots were included, with flying platforms ranging from fighter jets (n=54), combat helicopters (n=27), transport helicopters (n=52) and transport aircraft (n=30). These were compared with the results from 17 ATCs. A marked notch in the frequency range of 4–6 kHz was demonstrated in the mean audiograms of all platforms pilots, progressing with ageing. Hearing threshold shifts in relation to measurements at recruitment were first noted at the age of 30 years, particularly at 4 kHz (mean shift of 2.97 dB, p=0.001). There was no statistical association between flying variables and hearing thresholds adjusted for age by logistic regression analysis.

Conclusions

The audiometric profile of IAF pilots has a pattern compatible with noise exposure, as reflected by characteristic noise notch. However, no flight variable was associated with deterioration of hearing thresholds, and no significant difference from non-flying controls (ATCs) was seen.

Noise exposure and auditory thresholds of German airline pilots: a cross-sectional study

OBJECTIVE

The cockpit workplace of airline pilots is a noisy environment. This study examines the hearing thresholds of pilots with respect to ambient noise and communication sound.

METHODS

The hearing of 487 German pilots was analysed by audiometry in the frequency range of 125 Hz-16 kHz in varying age groups. Cockpit noise (free-field) data and communication sound (acoustic manikin) measurements were evaluated.

RESULTS

The ambient noise levels in cockpits were found to be between 74 and 80 dB(A), and the sound pressure levels under the headset were found to be between 84 and 88 dB(A).The left-right threshold differences at 3, 4 and 6 kHz show evidence of impaired hearing at the left ear, which worsens by age.In the age groups <40/≥40 years the mean differences at 3 kHz are 2/3 dB, at 4 kHz 2/4 dB and at 6 kHz 1/6 dB.In the pilot group which used mostly the left ear for communication tasks (43 of 45 are in the older age group) the mean difference at 3 kHz is 6 dB, at 4 kHz 7 dB and at 6 kHz 10 dB. The pilots who used the headset only at the right ear also show worse hearing at the left ear of 2 dB at 3 kHz, 3 dB at 4 kHz and at 6 kHz. The frequency-corrected exposure levels under the headset are 7-11 dB(A) higher than the ambient noise with an averaged signal-to-noise ratio for communication of about 10 dB(A).

CONCLUSIONS

The left ear seems to be more susceptible to hearing loss than the right ear. Active noise reduction systems allow for a reduced sound level for the communication signal below the upper exposure action value of 85 dB(A) and allow for a more relaxed working environment for pilots.

Evaluation of Hearing Loss in Pilots

Objective

High-intensity noise sources with an increase in air traffic and sudden changes in atmospheric pressure can cause hearing loss in pilots. The main goal of this research is to examine hearing loss due to age, the total flight hours and aircraft types and to evaluate the effects of personal conditions that can influence the hearing level.

Methods

We examined the data of 234 Turkish pilots aged between 25 and 54 years who were examined due to the aviation Law for annual control from January 2005 to January 2014 at Başkent University Medical Faculty, Ankara Hospital. The audiometric results of the pilots were used. While 1, 2, 3, 4, 6, and 8 KHz were used for the airway threshold, 1, 2, and 4 KHz were used for the bone conduction threshold.

Results

According to the data of the 234 pilots, there was a significant correlation between high-frequency hearing loss and the total flight hours and pilots' ages. The average hearing loss was higher, particularly in the left ear, in pilots using helicopters than in those using other aircraft types. There was no statistically significant correlation between hearing loss and diabetes, hypercholesterolemia, high blood pressure, anemia, obesity, and smoking.

Conclusion

A significant correlation was observed between high frequency hearing loss and the total flight hours, pilots' age, and aircraft types in our study.

Simultaneous effects of noise exposure and smoking on OAEs

Noise is one of the most pervasive hazardous factors in the workplace. Noise-induced hearing loss (NIHL) is the most common disorder related to noise exposure. Smoking is probably associated with hearing loss. The simultaneous effect of noise and smoking on hearing is a recent concern. In this study, we assessed the simultaneous effect of noise and smoking on standard pure tone audiometry (PTA) and distortion product otoacoustic emissions (DP-OAEs). This was an historical cohort study on 224 workers exposed to noise who were divided into two groups: Smokers and nonsmokers. DP-OAE response amplitudes were assessed. Data were analyzed by SPSS software (version 19) using Student's t-test and Mann-Whitney U test. One hundred and five subjects were smokers (case group) and 119 individuals were nonsmokers (control group). All the subjects were exposed to 91.08 + 2.29 dBA [time-weighted average (TWA) for an 8 h work shift]. Mean DP-OAE response amplitude at frequencies higher than 1,000 Hz was significantly higher in the smokers than the nonsmokers. This study showed that smoking can aggravate the effect of noise on hearing in DP-OAEs.

Occupational noise exposure and hearing: a systematic review

Purpose

To give a systematic review of the development of noise-induced hearing loss (NIHL) in working life.

Methods

A literature search in MEDLINE, Embase, Web of Science, Scopus, and Health and Safety Abstracts, with appropriate keywords on noise in the workplace and health, revealed 22,413 articles which were screened by six researchers. A total of 698 articles were reviewed in full text and scored with a checklist, and 187 articles were found to be relevant and of sufficient quality for further analysis.

Results

Occupational noise exposure causes between 7 and 21 % of the hearing loss among workers, lowest in the industrialized countries, where the incidence is going down, and highest in the developing countries. It is difficult to distinguish between NIHL and age-related hearing loss at an individual level. Most of the hearing loss is age related. Men lose hearing more than women do. Heredity also plays a part. Socioeconomic position, ethnicity and other factors, such as smoking, high blood pressure, diabetes, vibration and chemical substances, may also affect hearing. The use of firearms may be harmful to hearing, whereas most other sources of leisure-time noise seem to be less important. Impulse noise seems to be more deleterious to hearing than continuous noise. Occupational groups at high risk of NIHL are the military, construction workers, agriculture and others with high noise exposure.

Conclusion

The prevalence of NIHL is declining in most industrialized countries, probably due to preventive measures. Hearing loss is mainly related to increasing age.

Electronic supplementary material

The online version of this article (doi:10.1007/s00420-015-1083-5) contains supplementary material, which is available to authorized users.

Concurrent effect of noise exposure and smoking on extended high-frequency pure-tone thresholds

OBJECTIVE

Concurrent effect of noise and smoking on hearing loss is a recent concern. In this study, the concurrent effect of noise and smoking on hearing loss in conventional frequencies and frequencies higher than 8 kHz was assessed.

DESIGN

This was a cross-sectional study on workers exposed to noise who were divided into two groups: smokers and non-smokers. Hearing thresholds were assessed by conventional audiometry, and HFA. Data were analysed using non-parametric tests and Student's t-test.

STUDY SAMPLE

There were 212 workers.

RESULTS

Ninety-seven subjects were smokers and 115 individuals were non-smokers. All subjects were exposed to 92.1 ± 2.4 dBA (Leq8h). The highest threshold in conventional and high-frequency audiometry was observed at 6 kHz and 16 kHz, respectively. Hearing threshold at frequencies above 1 kHz was significantly higher in the smokers than non-smokers. There was no correlation between hearing thresholds and pack-years of smoking.

CONCLUSIONS

Concurrent exposure to noise and smoking may be associated with more hearing loss than exposure to noise alone in the conventional and high frequencies. However, other differences between smokers and non-smokers may explain these differences as well.

Hearing status among Norwegian train drivers and train conductors

Background

There is a general perception that train drivers and conductors may be at increased risk of developing noise-induced hearing loss.

Aims

To study job-related hearing loss among train drivers and train conductors.

Methods

Audiograms from train drivers and train conductors were obtained from the medical records of the occupational health service of the major Norwegian railway company. The results were compared with audiograms from an internal control group of railway workers and an external reference group of people not occupationally exposed to noise. The monaural hearing threshold level at 4kHz, the mean binaural value at 3, 4 and 6kHz and the prevalence of audiometric notches (≥25 dB at 4kHz) were used for comparison.

Results

Audiograms were available for 1567 drivers, 1565 conductors, 4029 railway worker controls and 15 012 people not occupationally exposed to noise. No difference in hearing level or prevalence of audiometric notches was found between study groups after adjusting for age and gender.

Conclusions

Norwegian train drivers and conductors have normal hearing threshold levels comparable with those in non-exposed groups.