Asymmetry in Noise-Induced Hearing Loss: Evaluation of Two Competing Theories

Details

• Personal Author:
  Berg RL ; Linneman JG ; Marlenga B ; Pickett W ; Wood DJ
• Description:
  Competing theories exist about why asymmetry is observed in noise-induced hearing loss (NIHL). We evaluated these theories using a cohort of young workers studied over 16 years. The study aim was to describe and evaluate patterns of hearing loss and asymmetry by gender, agricultural exposure and gunfire exposure. This was a secondary analysis of data collected from young adults during follow-up of a randomized controlled trial. This follow-up study evaluated long-term effects of a hearing conservation intervention for rural students. The sample consisted of 392 of 690 participants from the original trial. In total, 355 young adults (aged 29-33 years) completed baseline and follow-up noise exposure surveys and clinical audiometric examinations. Data are displayed graphically as thresholds by frequency and ear and degree of asymmetry between ears (left minus right). In the primary group comparisons, low and high frequency averages and mean high frequency asymmetry were analyzed using mixed linear models. At frequencies >2000 Hz, men showed more hearing loss, with greater asymmetry and a different asymmetry pattern, than women. For men with documented hearing loss, there was a trend toward increasing asymmetry with increasing levels of hearing loss. Asymmetry at high frequencies varied substantially by level of shooting exposure. While "head shadowing" is accepted as the primary explanation for asymmetric hearing loss in the audiologic and related public health literature, our findings are more consistent with physiological differences as the primary cause of asymmetric hearing loss, with greater susceptibility to NIHL in the left ear of men. [Description provided by NIOSH]
• Subjects:
  Agriculture Cohort Studies Health Promotion Hearing Loss, Noise-Induced Noise Noise, Occupational Occupational Health Safety Sex Characteristics
• Keywords:
  Agricultural Workers Asymmetry Auditory System Author Keywords: Agriculture Cohort Studies Gender Factors Health Promotion Hearing Tests Noise-induced Hearing Loss Noise Exposure Noise Induced Hearing Loss Young Workers

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• ISSN:
  1463-1741
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 5 ; Wisconsin
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  102-107
• Volume:
  16
• Issue:
  69
• NIOSHTIC Number:
  nn:20053047
• Citation:
  Noise Health 2014 Mar-Apr; 16(69):102-107
• Contact Point Address:
  Dr. Barbara Marlenga, National Farm Medicine Center, Marshfield Clinic Research, Foundation, 1000 North Oak Avenue, Marshfield, WI 54449, USA
• Email:
  marlenga.barbara@mcrf.mfldclin.edu
• Federal Fiscal Year:
  2014
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Performing Organization:
  Marshfield Clinic Research Foundation
• Peer Reviewed:
  True
• Start Date:
  20080801
• Source Full Name:
  Noise & Health
• End Date:
  20120731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:275a6899b9112297bc92ae9ad2ef3e52dfb3cd7d9fd35102f865181c3d45092702e88e523c21464983968247a02bb6190244bfc09e022185488783add0083138
• Download URL:
  https://stacks.cdc.gov/view/cdc/215900/cdc_215900_DS1.pdf
• File Type:
  [PDF - 955.59 KB ]