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Hearing loss is a common condition that affects millions of people regardless of age, ethnicity, and health status. Appropriate treatment for hearing loss depends greatly on the underlying pathophysiology and the severity of the condition. Pure-tone audiometry is a critical means of obtaining diagnostic information to guide healthcare providers toward appropriate treatment. Appropriate treatment for hearing loss depends significantly on the pathophysiology and the severity of the condition, and a detailed hearing assessment provides the healthcare team with the necessary diagnostic information to guide treatment. This activity reviews the details of pure-tone audiometry evaluation, including clinical appropriateness and utility, and examines the role of the interprofessional team in the evaluation and management of patients with otologic complaints. Objectives: Identify the difference between air conduction and bone conduction pure-tone evaluation. Assess the clinical utility of pure-tone audiometric threshold assessment. Evaluate when a clinically significant asymmetry of pure-tone thresholds is present. Access free multiple choice questions on this topic.

Hearing loss is a widespread chronic condition affecting over 25 million people aged 12 years or older in the United States. It may affect 1 in 5 children, temporarily or permanently, by the age of 18.[1][2] Despite the high prevalence of hearing loss, many adults do not receive appropriate or timely evaluation and treatment for their hearing concerns.[3] Appropriate treatment for hearing loss depends greatly on the pathophysiology and the severity of the condition, and a detailed hearing assessment provides the healthcare team with the necessary diagnostic information to guide treatment. While Weber and Rinne tuning fork tests are useful for clinical screening and identifying the type of hearing loss, they may miss nuances such as mild hearing loss, bilateral hearing loss, or mixed conductive and sensorineural hearing loss.[4][5] Pure-tone (isolated frequency) audiometry evaluation over the range of frequencies important for everyday listening can determine the degree, configuration, and type of hearing loss in a manner detailed enough to assist the healthcare team in determining the etiology and prognosis for the hearing loss as well as the optimal treatment strategy.[6]

Multiple factors can affect the outcomes or accuracy of pure-tone evaluation. Pure-tone thresholds can vary slightly with different transducers and transducer placement or in patient alertness and attention variations. In adults, standard diagnostic test-retest variability is typically ±5 dB across frequencies.[20] The pediatric population's test-retest variability may be as great as +/-10 dB.[35] A masking dilemma occurs when the amount of masking noise necessary to prevent sound crossover of a tone to the NTE is loud enough to cross back to the test ear and falsely elevate the evaluated threshold.[36] This occurs most commonly with severe bilateral conductive hearing loss.[37] See Graph. Conductive Hearing Loss. Otalgia, particularly of the pinna or auditory canal, may prevent the appropriate placement of headphones for air conduction. Supra-aural headphones are necessary in cases of atresia, but when stenotic or partially occluded canals are involved, the pressure they apply may cause canal obstruction and introduce a false conductive component.[38] Insert earphones can prevent external auditory canals from collapsing during testing and reduce the incidence of masking dilemmas.[39] Additionally, due to the differences in calibration between inserted earphones and headphones, the larger cavity created by tympanostomy tubes can cause low-frequency thresholds to be falsely elevated when using inserted earphones.[40] Behavioral complications include false positive responses, which can result from confusing tinnitus with the presented tone, responding to a regular rhythm of tone presentation, or over-eagerness to "do well" on the evaluation, particularly when a "passing score" is required for employment qualification. False negatives may occur when a patient does not provide consistent responses to audible tones due to a lack of understanding of testing procedures, a deficit in central processing, or a non-organic deficit caused by malingering or factitious disorders.[41] A Stenger test may be used to assess for malingering in a unilateral or asymmetric hearing loss by observing how the patient responds to a pure tone presented simultaneously to both ears when 1 tone is easily audible in the better-hearing ear but is quieter than the apparent threshold in the ear with greater hearing loss.[42]

Behavioral complications include false positive responses, which can result from confusing tinnitus with the presented tone, responding to a regular rhythm of tone presentation, or over-eagerness to "do well" on the evaluation, particularly when a "passing score" is required for employment qualification. False negatives may occur when a patient does not provide consistent responses to audible tones due to a lack of understanding of testing procedures, a deficit in central processing, or a non-organic deficit caused by malingering or factitious disorders.[41] A Stenger test may be used to assess for malingering in a unilateral or asymmetric hearing loss by observing how the patient responds to a pure tone presented simultaneously to both ears when 1 tone is easily audible in the better-hearing ear but is quieter than the apparent threshold in the ear with greater hearing loss.[42] If the patient responds because they hear the quiet tone in the better-hearing ear, the Stenger test is negative, and the hearing loss may be considered accurate. If the patient does not respond, which typically occurs because the patient deliberately does not respond to the louder tone in the tested ear and does not realize a quieter tone in the NTE, the Stenger is positive and indicates at least some degree of exaggeration in the responses. Stenger testing has a high sensitivity for detecting unilateral non-organic hearing loss.[43]

Hearing loss is the third most common chronic health condition in aging adults and affects 1 in 5 children to some degree by the age of 18. Relationships between the severity of hearing loss and the severity of ear disease, as well as the relationships between hearing loss and communication, social, and educational deficits in children, make catching hearing loss early a critical healthcare task. Pure-tone audiometry is a low-risk, low-cost procedure but can provide crucial information regarding differential diagnosis, symptom etiology or pathophysiology, and guidance for appropriate treatment. Any time a hearing loss or abnormal auditory perception is reported as a symptom, a referral to audiology for testing that includes pure-tone evaluation should be part of the evaluation process.[1][8] If a concern about hearing is not addressed, negative outcomes range from developmental delays to poorer quality of life to debilitating disability.[56][57][58] The close correlation between ear health and hearing abnormalities makes coordination between otolaryngologists and audiologists critical. Pure-tone testing is also key for pre-and post-treatment evaluation when outcome measures include the preservation or improvement of hearing as a significant indicator of efficacy, such as for idiopathic sudden sensorineural hearing loss, and otologic surgeries, including tympanoplasty, stapedotomy, semicircular canal dehiscence resurfacing, or mastoidectomy.[59][60][61] Due to the myriad causes of hearing loss, care coordination among healthcare providers relying on pure-tone audiometry may include general practitioners, pediatricians, otolaryngologists, oncologists, neurologists, speech-language pathologists, and audiologists. Inter-professional communication and care coordination are essential for evidence-based, timely management of patients and optimal treatment outcomes.k