September 20, 2007

This week was the busiest week I have had since clinic started. Yesterday I saw 3 of the 4 clients scheduled. Two of the clients were DPS and I had one little girl. All of the clients had thresholds within normal limits. We did not obtain thresholds for the little girl, but instead obtained minimum response levels. We noticed the two DPS officers had a noise notch at 6000 Hz. Due to this finding, we recommended they continue to use hearing protection whenever they were exposed to loud sounds. For the two DPS officers, we did use otoacoustic emissions testing.

Since otoacoustic emissions are a bit of a mystery to me, I thought I would look up an article to help me understand.
The article I found was about the effects of aging and hearing loss on distortion product otoacoustic emissions. In the article, they were trying to demonstrate the rate of change in DPOAE amplitude with age in relation to hearing loss in an adult population. The researchers did a cross-sectional observation study involved the Framingham Offspring Cohort. The results from their study showed that women had a mean hearing threshold-adjusted loss in high-frequency DPOAE amplitude of 0.6, 2.1, 2.6, and 1.1 dB/per decade at the f2 frequencies of 1, 2, 4, and 8 kHz. The men showed no effect of age on the DPOAE amplitude independent of hearing loss.

Reference:
Cilento, B.W., Norton, S.J., Gates, G.A. (2003). The effects of aging and hearing loss on distortion product otoacoustic emissions. Otolaryngology-Head and Neck Surgery 129 (4), 382-389.

If you would like to read this article, please check out the following link:
http://web.ebscohost.com/ehost/detail?vid=7&hid=8&sid=594518b8-36fc-4c5c-85b1-9fb232472d9b%40sessionmgr108