OCCUPATIONAL NOISE AND CHEMICAL EXPOSURE EFFECTS ON AUDITORY AND VESTIBULAR FUNCTION

September 4, 2026 updated by: Handan Turan Dizdar, Ondokuz Mayıs University

EFFECTS OF OCCUPATIONAL NOISE AND CHEMICAL EXPOSURE ON AUDITORY AND VESTIBULAR FUNCTION IN FUEL STATION EMPLOYEES

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.

Study Overview

Status

Not yet recruiting

Conditions

Occupational Noise Exposure

Study Type

Observational

Enrollment (Estimated)

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Name: Handan TURAN DİZDAR, PhD
Phone Number: +90 505 597 06 27
Email: handan.dizdar@omu.edu.tr

Study Contact Backup

Name: Işılay Kaplan, Audiologist
Phone Number: +90 555 897 03 66
Email: isilaykplan66@gmail.com

Study Locations

Turkey (Türkiye)
- - Samsun, Turkey (Türkiye), 55139
    - Ondokuz Mayıs University
    - Contact:
      
      Ondokuz Mayıs University
      
      Phone Number: +90 362 312 19 19
      
      Email: iletisim@omu.edu.tr
    - Sub-Investigator:
      
      Handan TURAN DİZDAR, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Adult

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.

Description

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:

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pure-Tone Audiometry Hearing Thresholds Time Frame: Baseline	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.	Baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Acoustic Reflex Thresholds Time Frame: Baseline	Ipsilateral and contralateral acoustic reflex thresholds were assessed at 500, 1000, 2000, and 4000 Hz and compared between the study and control groups.	Baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Ondokuz Mayıs University

Investigators

Principal Investigator: Handan TURAN DİZDAR, PhD, Ondokuz Mayıs University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General 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.

Helpful Links

Vestibular Dysfunction - StatPearls, NCBI Bookshelf

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 3, 2026

Primary Completion (Estimated)

February 10, 2027

Study Completion (Estimated)

March 10, 2027

Study Registration Dates

First Submitted

September 2, 2026

First Submitted That Met QC Criteria

September 4, 2026

First Posted (Actual)

September 8, 2026

Study Record Updates

Last Update Posted (Actual)