CDC-NCHS-NHANES Audiometry Component

National Institute On Deafness And Other Communication Disorders

Investigators

Abstract

This interagency collaborative project will provide support to the National Center for Health Statistics (NCHS), CDC for implementation of nationally representative hearing health examinations and interview epidemiological survey questions for assessment of hearing thresholds and risk factors for hearing loss and related conditions such as hyperacusis and tinnitus in both children and adults. A special emphasis of the NHANES 2025-2026 epidemiological hearing examination and questionnaire component will be collection of data to assist in studies of hearing loss induced by noise, other ototraumatic, or ototoxic agents. In addition to exposure to noise from personal audio devices, many individuals are exposed to potentially hazardous levels of sound from noisy activities, such as concerts, music venues including bars or dance clubs, sporting events, motorcycles, recreational vehicles, mass transit systems, fireworks, and hunting or target shooting. An estimated 22 million U.S. workers are exposed each year to potentially hazardous noise on the job. As many as 26 million U.S. adults have developed a hearing loss as the result of their noise exposure—hearing losses that are nearly all preventable. This NHANES study also includes blood laboratory assays that will allow research investigators to examine chemical exposure to lead, solvents, and carbon monoxide (e.g., cigarette smoking) effects that cause damage to the ear. These data will also be available as a comparison dataset in future studies of hearing loss, and as a baseline to monitor progress in prevention. The current protocol for the hearing examination component was developed by NCHS in collaboration with the National Institute on Deafness and Other Communication Disorders (NIDCD) and the National Institute for Occupational Safety and Health (NIOSH). The target group for the audiometry exam are Survey Participants (SPs) 12–44 years old. The component includes four parts: 1) Questionnaire items. Hearing-related questions are included in the household questionnaire and in the Mobile Examination Center (MEC) pre-exam questionnaire. Questionnaire items collect information on self-reported hearing ability; use of hearing aids and hearing protective devices; relevant medical history; noise exposure history; and conditions that could affect the results of audiometric testing. 2) Otoscopy. A cursory physical examination is conducted of the outer ear. A photo of the SP’s eardrum in each ear is captured with a digital otoscope and sent to NIOSH for interpretation. 3) Tympanometry. An objective evaluation of middle ear function is conducted based on the movement of the eardrum as pressure is varied in the ear canal. 4) Pure tone air conduction audiometry (Hearing Test). A basic evaluation of hearing sensitivity is performed. Hearing thresholds are obtained at seven frequencies (500, 1,000, 2,000, 3,000, 4,000, 6,000, and 8,000 Hz) bilaterally, with a repeat threshold at 1,000 Hz in each ear to verify response consistency. The test is conducted automatically by an audiometer in a quiet space using boothless audiometry. Background noise in the test area is monitored continuously during pure tone audiometry testing. The measured noise levels are linked to each threshold. Thresholds that may have been contaminated by excessive background noise will be flagged in the dataset.