Evaluation of cochlear activity in normal-hearing musicians.

Objective: The present study compared wave I amplitude of auditory brainstem responses (ABRs), a potential indicator of cochlear synaptopathy, among musicians and non-musicians with normal audiograms.

Design: Noise exposure background (NEB) was evaluated using an online questionnaire. Two-channel ABRs were recorded from the left ear using click stimuli.

Student's music exposure: Full-day personal dose measurements.

Previous studies have shown that collegiate level music students are exposed to potentially hazardous sound levels. Compared to professional musicians, collegiate level music students typically do not perform as frequently, but they are exposed to intense sounds during practice and rehearsal sessions. The purpose of the study was to determine the full-day exposure dose including individual practice and ensemble rehearsals for collegiate student musicians.

Feasibility of a bilateral 4000-6000 Hz notch as a phenotype for genetic association analysis.

Objective: Noise-induced hearing loss (NIHL) is a worldwide health problem and a growing concern among young people. Although some people appear to be more susceptible to NIHL, genetic association studies lack a specific phenotype. We tested the feasibility of a bilateral 4000-6000 Hz audiometric notch as a phenotype for identifying genetic contributions to hearing loss in young adults.

Prevalence of noise-induced hearing loss in student musicians.

This study describes the prevalence and characteristics of noise-induced hearing loss (NIHL) in student musicians (N = 329) aged 18-25 years. Students completed a questionnaire regarding exposures before a hearing assessment. NIHL was defined by the presence of a notch 15 dB in depth at 4000 or 6000 Hz relative to the best preceding threshold.

Voiced initial consonant perception deficits in older listeners with hearing loss and good and poor word recognition.

Purpose: This study examined differences in voiced consonant-vowel (CV) perception in older listeners with normal hearing and in 2 groups of older listeners with matched hearing losses: those with good and those with poor word recognition scores.

Method: Thirty-six participants identified CVs from an 8-item display from the natural voiced initial consonants/b, d, g, m, n, eth, v and z/in three vowel contexts (/a, o, u/) spoken by a male and a female talker.

Results: The listeners with hearing loss and poor word recognition scores (WRS) made more of the same types of errors, as well as errors not made by listeners with hearing loss and good word recognition.

The effect of silence on tinnitus perception.

Objective: The effect of sustained silence was studied on the emergence of tinnitus perception in 120 normal hearing young adult Caucasians and African Americans.

Study Design And Setting: After sitting in a sound booth for a period of 20 minutes, participants were asked to complete a questionnaire documenting whether they perceived sounds in the silent setting and descriptions of the sounds they heard.

Results: Tinnitus-like sounds were perceived in 64% of listeners overall.

Response of desert biological soil crusts to alterations in precipitation frequency.

Biological soil crusts, a community of cyanobacteria, lichens, and mosses that live on the soil surface, occur in deserts throughout the world. They are a critical component of desert ecosystems, as they are important contributors to soil fertility and stability. Future climate scenarios predict alteration of the timing and amount of precipitation in desert environments.

Immunity to hepatitis A in people born and raised in endemic areas.

Background: Hepatitis A is the most common vaccine-preventable disease in international travelers. Many individuals born and raised in hepatitis A endemic areas are likely to be immune to hepatitis A. Unnecessary hepatitis A immunization could be avoided by taking into account prior exposure to hepatitis A and judicious use of serotesting prior to immunization.

Monosoonal precipitation responses of shrubs in a cold desert community on the Colorado Plateau.

South-eastern Utah forms a northern border for the region currently influenced by the Arizona monosoonal system, which feeds moisture and summer precipitation into western North America. One major consequence predicted by global climate change scenarios is an intensification of monosoonal (summer) precipitation in the aridland areas of the western United States. We examined the capacity of dominant perennial shrubs in a Colorado Plateau cold desert ecosystem of southern Utah, United States, to use summer moisture inputs.

Comparisons of carbon isotope discrimination in populations of aridland plant species differing in lifespan.

Carbon isotope discrimination (Δ) was compared between populations of dominant perennial plant species, differing in life expectancy, in two deserts with contrasting vegetation types. In both deserts, plants of the shorter-lived species showed significantly higher Δ and greater intrapopulation variance in this character compared to the long-lived species. These results indicate underlying differences in gas-exchange physiology, and suggest a positive correlation between water-use efficiency and lifespan in desert plants.

Differential utilization of summer rains by desert plants.

Seasonal changes in the hydrogen isotope ratios of xylem waters were measured to determine water sources used for growth in desert plants of southern Utah. While all species used winter-spring recharge precipitation for spring growth, utilization of summer rains was life-form dependent. Annuals and succulent perennials exhibited a complete dependence on summer precipitation.