This article and any supplementary material should be cited as follows: Wilson RH, McArdle R. Characteristics of audiometric 4,000 Hz notch (744,553 veterans) and 3,000, 4,000, and 6,000 Hz notches (539,932 veterans). J Rehabil Res Dev. 2013;50(1):111– Slideshow Project DOI: /JRRD JSP Characteristics of audiometric 4,000 Hz notch (744,553 veterans) and 3,000, 4,000, and 6,000 Hz notches (539,932 veterans) Richard H. Wilson, PhD; Rachel McArdle, PhD
This article and any supplementary material should be cited as follows: Wilson RH, McArdle R. Characteristics of audiometric 4,000 Hz notch (744,553 veterans) and 3,000, 4,000, and 6,000 Hz notches (539,932 veterans). J Rehabil Res Dev. 2013;50(1):111– Slideshow Project DOI: /JRRD JSP Aim – Examine prevalence and characteristics of audiograms notched at 4,000 Hz and at 3,000, 4,000, and/or 6,000 Hz. – Extend findings from previous local group of veterans to substantially larger national group of veterans. Relevance – Air-conduction audiograms with 3,000, 4,000, and/or 6,000 Hz thresholds at higher hearing levels than adjacent 2,000 and 8,000 Hz thresholds are known as “notched audiograms.”
This article and any supplementary material should be cited as follows: Wilson RH, McArdle R. Characteristics of audiometric 4,000 Hz notch (744,553 veterans) and 3,000, 4,000, and 6,000 Hz notches (539,932 veterans). J Rehabil Res Dev. 2013;50(1):111– Slideshow Project DOI: /JRRD JSP Method Bilateral audiograms from ~1 million veterans were obtained from Department of Veterans Affairs archives. After “cleaning” algorithms, 2 analysis groups formed: – Group 1 (4,000 Hz notch analysis) 744,553 participants (mean age 63.5 yr). – Group 2 (3,000, 4,000, and/or 6,000 Hz notch analysis) 539,932 participants (mean age 62.2 yr).
This article and any supplementary material should be cited as follows: Wilson RH, McArdle R. Characteristics of audiometric 4,000 Hz notch (744,553 veterans) and 3,000, 4,000, and 6,000 Hz notches (539,932 veterans). J Rehabil Res Dev. 2013;50(1):111– Slideshow Project DOI: /JRRD JSP Results Group 1: – 77.1% did not have 4,000 Hz notch. Group 2: – 65.3% did not have 3,000, 4,000, or 6,000 Hz notch. – 12.4% had bilateral notches. Left vs right ear: – 11.7% had left ear notches. – 10.7% had right ear notches. Low vs high frequency: – Notches about twice as deep on low-frequency side of notch than high- frequency side. Notch depth about same (23 dB) in both ears.
This article and any supplementary material should be cited as follows: Wilson RH, McArdle R. Characteristics of audiometric 4,000 Hz notch (744,553 veterans) and 3,000, 4,000, and 6,000 Hz notches (539,932 veterans). J Rehabil Res Dev. 2013;50(1):111– Slideshow Project DOI: /JRRD JSP Conclusion Finding of more unilateral than bilateral notches prompts at least two hypotheses: – High-frequency notches are caused by multiple factors, including excessive noise exposure. – The ears are differentially sensitive to whatever factors are eventually found to be responsible for high-frequency audiometric notches.