Noise-Induced Hearing Loss clinical trials

ABR Characteristics and Salivary Cortisone Concentration in Noise-exposed Workers

The aim of the research: Investigate the association of auditory evoked brainstem response characteristics with salivary cortisone concentrations in noise-exposed workers. Purpose of the research: 1. Investigate the magnitude of the amplitudes and latencies of auditory brainstem responses. 2. Investigate the concentration of cortisone in saliva. 3. To investigate the correlation of the characteristics of auditory evoked brainstem potentials with the age of the subjects or the length of work in noise. 4. Investigate the association of salivary cortisone concentration with subjects' age or length of work in noise. 5. Investigate the prevalence of mild, moderate and severe hearing impairment in the 19-35 age group. 6. Investigate the relationship of hearing threshold shift with the age of the subjects or the length of work in noise. 7. To investigate the difference in the characteristics of auditory evoked brainstem potentials and the difference in salivary cortisone concentration between subjects with a bilaterally normal hearing threshold (≤25 dB) at high frequencies and subjects with unilaterally or bilaterally increased hearing threshold (> 25 dB) at high frequencies . 8. Investigate the perceived stress and psychosocial risk factors in the workplace and their relationship to salivary cortisone concentrations. Research Hypothesis: There is an association between the characteristics of auditory evoked brainstem response and salivary cortisone concentrations in noise-exposed workers. Research participants Inclusion criteria: 1. male and female 2. ages 19-35 3. exposure to noise level ≥ 85 dB (A) per week at the workplace 4. work in noise from 1 to 16 years 5. workplace not involving exposure to carbon disulfide or a mixture of organic solvents that have toxic effects on the ear (toluene, xylene and styrene) 6. unilaterally or bilaterally normal otoscopic findings 7. unilaterally or bilaterally tympanogram: peak pressure value ± 50 daPa at 226 Hz with eardrum mobility of 0.3 to 1.3 mL Exclusion criteria: 1. information about an earlier sudden hearing loss 2. information on chronic middle ear inflammation 3. information on ear surgery (except placement of ventilation tubes in the eardrum) 4. information on dizziness associated with hearing loss and noise 5. information on insomnia 6. current use of oral corticosteroids 7. bilaterally found air-bone gap greater than 15 dB