Hearing loss has been associated with poor vitamin B12 status in some, but not all studies. This study examined a possible relationship between age-related hearing loss and poor B12 status in 93 older adults using different indices of B12 status. Hearing loss was defined as pure-tone average threshold > 25 decibel hearing level. Participants with methylmalonic acid (MMA) > 271 nmol/L at baseline received 1,000 g/d, and those with MMA < or = 271 nmol/L were randomly assigned to receive 0, 25, or 100 microg/d of B12. In a series of logistic regression analyses, compared with participants with normal hearing, those with impaired hearing had a significantly higher serum mean MMA concentrations in the best and the worst ears and a higher prevalence of elevated MMA (> 271 nmol/L) in the worst ear only. Thus, elevated MMA concentration may be associated with hearing loss in older adults. However, short-term B12 supplementation was unrelated to improvements in hearing status in B12-deficient individuals.

: Basic knowledge of white‐tailed deer (Odocoileus virginianus) hearing can improve understanding of deer behavior and may assist in the development of effective deterrent strategies. Using auditory brainstem response testing, we determined that white‐tailed deer hear within the range of frequencies we tested, between 0.25–30 kilohertz (kHz), with best sensitivity between 4–8 kHz. The upper limit of human hearing lies at about 20 kHz, whereas we demonstrated that white‐tailed deer detected frequencies to at least 30 kHz. This difference suggests that research on the use of ultrasonic (frequencies >20 kHz) auditory deterrents is justified as a possible means of reducing deer—human conflicts.

Reference threshold sound-pressure levels were established for a new insert earphone, the ER-3A tubephone, and for the TDH-50 earphone. In test-retest comparisons, the tubephone produced estimates of auditory threshold as reliable as the thresholds produced by the supraaural earphone. Reference thresholds were developed for the two earphones from data contributed by three laboratories. While the TDH-50 data are in good agreement with the provisional ANSI 6-cc coupler reference levels (ASHA, 1982), the ER-3A data are at variance with the manufacturer's provisional recommendation for 2-cc coupler reference thresholds for frequencies below 1 kHz. The differences are attributed to physiologic noise that masked the lower frequency thresholds.

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