Normal Values in Hearing and Balance Testing

Eligibility Criteria

• * Healthy adults, aged 18-80 years
• * Able to provide informed consent
• * Normal hearing sensitivity, defined as pure-tone thresholds less than or equal to 25 dB HL, or when the pure-tone threshold exceeds 25 dB HL, it must be less than or equal to the median threshold for the appropriate gender- and age-based group, for 250-8000 Hz (Morrell et al, 1996, ISO-7029, 2000).
• * No air-bone gaps in excess of 10 dB for 500-4000 Hz.
• * Normal middle ear function as indicated by normal 226 Hz tympanograms bilaterally, defined as middle ear pressure between more or less 100 decaPascals, and peak compensated static compliance between 0.3-1.5 milliliters
• * American English as a first language for those participating in study tasks evaluating auditory processing.
• * Able to refrain from caffeine and alcohol for 48 hours before vestibular study sessions because both agents may modify the test results.
• * History of auditory and/or vestibular disorders (e.g., Meniere s syndrome, labyrinthitis).
• * Evidence of active outer or middle ear disease or anomaly (e.g. otitis media, stenotic ear canal, otorrhea)
• * History of chronic (fluid in middle ear for more than 4 months) or recurrent otitis media (more than 4 episodes of acute otitis media in one year)
• * History of ear surgery other than PE tubes
• * Current PE tubes
• * History of treatment with ototoxic medications (e.g. cisplatin, aminoglycoside antibiotics)
• * Unable to discontinue medications that can interfere with vestibular test results for the 48 hours immediately preceding a vestibular study session. These include any and all anti-dizziness medications (such as Antivert), prescription pain medications (such as Percocet), prescription headache medications (such as Imitrex), sleeping pills (such as Ambien), anti-seizure medications (such as Topamax), and/or antihistamines (such as Benadryl).
• * Current diagnosis from the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) of a psychiatric disorder or on medications for a psychiatric disorder in the past two years, including any or all antidepressants, anxiolytics, or psychostimulant drugs.
• * Cognitive impairment as evidenced by a score \<26 on the Montreal Cognitive Assessment (MoCA).
• * Attention deficit hyperactivity disorder (ADHD) as evidenced by a score of greater than or equal than or equal to 4 on the Adult ADHD Self Report Scale (Kessler et al., 2005).
• * History or diagnosis of a central nervous system disorder, including but not limited to:
• * Intracranial tumors
• * Cerebrovascular disease
• * Degenerative CNS disorder
• * CNS trauma
• * Encephalitis
• * Meningitis
• * Current diagnosis of speech and/or language disorders, autism, auditory neuropathy, or auditory processing disorder; or in therapy for these disorders in past 2 years.
• * Reduced visual acuity preventing ability to see the visual targets used for vestibular and balance testing as evidenced by corrected visual acuity worse than 20/25 on a Snellen chart for those participating in vestibular tasks.
• * Ocular motor impairment preventing ability accurately follow the visual target used for calibration and/or ocular motor tasks for those participating in the vestibular tasks.
• * Employees and staff of the Audiology Unit, Otolaryngology Branch, NIDCD.
• * Reduced balance or postural instability as evidenced by a Timed Up and Go score greater than or equal to 11.1 seconds (Whitney et al., 2004) for adults \<65 years of age and \>12.6 seconds for adults 65-80 years of age (Shumway-Cook et al.,2000) and/or Activities-specific Balance Confidence Score \<67% for those participating in vestibular study tasks.