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Not yet recruitingNCT07806123Updated Sep 8, 2026

OCCUPATIONAL NOISE AND CHEMICAL EXPOSURE EFFECTS ON AUDITORY AND VESTIBULAR FUNCTION

An observational study in Occupational Noise Exposure, sponsored by Ondokuz Mayıs University. Not yet recruiting at 1 site in Turkey (Türkiye). Open to male participants aged 20 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-08.

Sponsored by Ondokuz Mayıs University · Observational

Study type
Observational
Model
Cohort
Time perspective
Cross-sectional
Enrollment
50
Ages
20 Years to 60 Years
Sex
Male
01

Study summary

This study aims to investigate the effects of occupational noise exposure on hearing and auditory functions among individuals working in noisy environments. The study evaluates the relationship between occupational noise exposure and hearing-related outcomes.

02

Conditions studied

  • Occupational Noise Exposure

Keywords

  • Chemical esposure
  • Fuel station employees
  • Noise-induced hearing loss
  • Occupational exposure
  • Ototoxicity
  • Vestibulotoxicity
03

In context

Hearing Loss, Noise-Induced

46 studies on the registry are indexed under Hearing Loss, Noise-Induced; 10 are open to participants now.

This study's planned enrollment of 50 is below the median of 200 across 14 observational studies indexed under Hearing Loss, Noise-Induced.

Browse Hearing Loss, Noise-Induced studies →

Lead sponsor

Ondokuz Mayıs University is the lead sponsor of 277 studies on the registry; 62 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
20 Years to 60 Years
Sexes eligible
Male
Accepts healthy volunteers
Yes
Sampling method
Non-probability sample

Study population

Fuel station employees aged 20-60 years and healthy individuals with similar sociodemographic characteristics who had no occupational exposure to noise or chemicals.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Male participants aged 20-60 years who had been working at a fuel station for at least two years, had no hearing loss on their pre-employment audiogram, and had no history of balance loss or otologic surgery.

Exclusion criteria

Exclusion Criteria:

  • Individuals with middle ear pathology, a history of hearing loss, vestibular disease, or neurological or psychiatric disorders.
05

Study design

Observational model
Cohort
Time perspective
Cross-sectional
Enrollment
50 participants (estimated)
Patient registry
No

Groups and cohorts

  • Study Group

    Fuel station workers exposed to occupational noise and chemical substances.

  • Control Group

    Healthy individuals with similar sociodemographic characteristics and no exposure to occupational noise or chemical substances.

06

What researchers measure

Primary outcomes

  1. Pure-Tone Audiometry Hearing Thresholds

    Hearing thresholds were assessed by pure-tone audiometry at 250, 500, 1000, 2000, and 4000 Hz in both ears and compared between the study and control groups.

    Time frame: Baseline

Secondary outcomes

  1. Acoustic Reflex Thresholds

    Ipsilateral and contralateral acoustic reflex thresholds were assessed at 500, 1000, 2000, and 4000 Hz and compared between the study and control groups.

    Time frame: Baseline

07

Study locations

1 site
08

References and documents

Publications

  • Roggia SM, de Franca AG, Morata TC, Krieg E, Earl BR. Auditory system dysfunction in Brazilian gasoline station workers. Int J Audiol. 2019 Aug;58(8):484-496. doi: 10.1080/14992027.2019.1597286. Epub 2019 Apr 24. PubMed 31017499 ↗

Individual participant data

Plan to share: No — Individual participant data will not be shared with other researchers. Only aggregate study results will be reported in the publication.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Sep 8, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07806123
Responsible party
Handan Turan Dizdar (Assistant Professor, Ondokuz Mayıs University) — Principal investigator
First posted
Sep 8, 2026
Start date
Sep 3, 2026 (estimated)
Primary completion
Feb 10, 2027 (estimated)
Completion
Mar 10, 2027 (estimated)
Last update
Sep 8, 2026

Study contacts

Handan TURAN DİZDAR, PhD
Contact
handan.dizdar@omu.edu.tr
+90 505 597 06 27
Işılay Kaplan, Audiologist
Contact
isilaykplan66@gmail.com
+90 555 897 03 66
Handan TURAN DİZDAR, PhD
principal investigator · Ondokuz Mayıs University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.

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Discussion

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