Background Falls and fall-related injuries are a major public health concern. HIV-infected adults have been shown to have a high incidence of falls. Identification of major risk factors for falls that are unique to HIV or similar to the general population will inform development of future interventions for fall prevention. Methods HIV-infected and uninfected men and women participating in a Hearing and Balance Sub-study of the Multicenter AIDS Cohort Study and Women’s Interagency HIV Study were asked about balance symptoms and falls during the prior 12 months. Falls were categorized as 0, 1, or ≥ 2; proportional odds logistic regression models were used to investigate relationships between falls and demographic and clinical variables and multivariable models were created. Results 24% of 303 HIV-infected participants reported ≥1 fall compared to 18% of 233 HIV-uninfected participants (p=0.27). HIV-infected participants were demographically different from HIV-uninfected participants, and were more likely to report clinical imbalance symptoms (p≤0.035). In univariate analyses, more falls were associated with hepatitis C, female sex, obesity, smoking, and clinical imbalance symptoms, but not age, HIV serostatus, or other comorbidities. In multivariable analyses, female sex and imbalance symptoms were independently associated with more falls. Among HIV-infected participants, smoking, number of medications, and imbalance symptoms remained independent fall predictors while current protease inhibitor use was protective. Discussion Similar rates of falls among HIV-infected and uninfected participants were largely explained by a high prevalence of imbalance symptoms. Routine assessment of falls and dizziness/imbalance symptoms should be considered, with interventions targeted at reducing symptomatology.

As supplement to a general health screening examination (HUNT-II), we conducted a puretone audiometry study in 1996-98 on adults (>20 years) in 17 of 23 municipalities in Nord-Trøndelag, Norway, including questionnaires on occupational and leisure noise exposure, medical history, and symptoms of hearing impairment. The study aims to contribute to updated normative hearing thresholds for age and gender, while evaluating the effects of noise exposure, medical history, and familial or genetic influences on hearing. This paper presents the unscreened hearing threshold data and prevalence of hearing impairment for different age groups and by gender. Valid audiometric data were collected from 62% (n=50,723) of 82,141 unscreened invited subjects (age-range 20-101 years, mean=50.2 years, SD=17.0 years). Two ambulant audiometric teams each conducted 5 parallel self-administered, pure-tone hearing threshold examinations with the standard test frequencies 0.25-0.5-1-2-3-4-6-8 kHz (manual procedure when needed). Tracking audiometers were used in dismountable booths with in-booth noise levels well within ISO criteria, except being at the criterion around 200 Hz. The data were electronically transferred to a personal computer. Test-retest correlations for 99 randomly drawn subjects examined twice were high. The mean thresholds recorded were some dB elevated from "audiometric zero" even for age group 20-24 years. As also found in other studies, this might indicate too restrictive audiometric reference thresholds. Males had slightly better hearing < or =0.5 kHz for all age groups. Mean thresholds were poorer in males > or = 30 years from > or =2 kHz, with maximal gender differences of approximately 20 dB at 3-4 kHz for subjects aged 55-74 years. Weighted prevalence data averaged over 0.5-1-2-4 kHz showed hearing impairment >25 dB hearing threshold level of 18.8% (better ear) and 27.2% (worse ear) for the total population--for males 22.2% and 32.0%, for females 15.9% and 23.0%, respectively. Mean hearing loss > or =10 dB at 6 kHz registered for both genders even in age groups 20-24 years may be partly due to calibration artefacts, but might possibly also reflect noise-related socio-acusis.

The NIH Toolbox project has assembled measurement tools to assess a wide range of human perception and ability across the lifespan. As part of this initiative, a small but comprehensive battery of auditory tests has been assembled. The main tool of this battery, pure-tone thresholds, measures the ability of people to hear at specific frequencies. Pure-tone thresholds have long been considered the "gold standard" of auditory testing, and are normally obtained in a clinical setting by highly trained audiologists. For the purposes of the Toolbox project, an automated procedure (NIH Toolbox Threshold Hearing Test) was developed that allows nonspecialists to administer the test reliably. Three supplemental auditory tests are also included in the Toolbox auditory test battery: assessment of middle-ear function (tympanometry), speech perception in noise (the NIH Toolbox Words-in-Noise Test), and self-assessment of hearing impairment (the NIH Toolbox Hearing Handicap Inventory Ages 18-64 and the NIH Toolbox Hearing Handicap Inventory Ages 641). Tympanometry can help differentiate conductive from sensorineural pathology. The NIH Toolbox Words-in-Noise Test measures a listener's ability to perceive words in noisy situations. This ability is not necessarily predicted by a person's pure-tone thresholds; some people with normal hearing have difficulty extracting meaning from speech sounds heard in a noisy context. The NIH Toolbox Hearing Handicap Inventory focuses on how a person's perceived hearing status affects daily life. The test was constructed to include emotional and social/situational subscales, with specific questions about how hearing impairment may affect one's emotional state or limit participation in specific activities. The 4 auditory tests included in the Toolbox auditory test battery cover a range of auditory abilities and provide a snapshot of a participant's auditory capacity. Neurology The human auditory system has the capacity to detect sounds, recognize and discriminate among sounds, comprehend the meaning of acoustic events, localize sound sources, and determine the direction and presence of sound movement. Hearing involves both the physical processing of acoustic signals (e.g., intensity and frequency) and their psychological percepts (e.g., loudness and pitch). Humans can detect, discriminate, and localize a wide variety of auditory stimuli, including linguistic sounds (e.g., speech syllables, words, sentences), and nonlinguistic sounds (e.g., clicks, tones, music). Audition research, traditionally concerned primarily with functions supported by mechanisms in the auditory periphery, has recently begun to examine more central aspects of processing auditory information and the role of hearing as it relates more broadly to human communication. 1Audition occurs when acoustic energy enters the outer ear and stimulates the eardrum (tympanic membrane), which transduces acoustic energy into mechanical energy. This mechanical energy is transmitted via the ossicles (malleus, incus, stapes) to the inner...