Practical approach for lateral canal benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) of the lateral semicircular canal is a well-recognized condition, even though there are controversies about the repositioning maneuvers and their efficacy. In recent decades, several maneuvers have been proposed for treating both apogeotropic and geotropic variants of lateral canal BPPV. Our purpose is to discuss a practical approach to this pathology with the Zuma maneuver. In a single session, this maneuver may be useful to treat patients with canalithiasis of the ampullary and non-ampullary arms, and cupulolithiasis with the otoliths in the canal and utricular side of the lateral canal.

The role of the reversed nystagmus during Zuma maneuver in patients treated for geotropic lateral canal benign paroxysmal positional vertigo.

INTRODUCTION: The geotropic variant of lateral canal BPPV occurs due to free floating otoconia in the non ampullary arm of this canal. Several repositioning maneuvers were effective to treat patients with this variant. We have previously proposed that the Zuma maneuver, first described for apogeotropic lateral canal BPPV, could also be effective for the geotropic variant as we believe that adopting a single maneuver may help the neurotological clinical practice. MATERIAL AND METHODS: Fifteen patients with geotropic lateral canal BPPV were enrolled and treated with Zuma maneuver. Patients were reevaluated 1 h after a single maneuver. RESULTS: All patients showed a nystagmus beating to the affected side in step I of Zuma maneuver that reversed its direction in step II. Besides, all patients achieved immediate resolution of vertigo and positional nystagmus after the application of the maneuver. CONCLUSIONS: The reversal of the nystagmus in step II of Zuma maneuver could be considered as a good prognostic indicator of the successful of this maneuver in patients with geotropic lateral canal BPPV. Moreover, despite the small sample of patients, Zuma maneuver was effective on short-term follow up for geotropic LC-BPPV after a single application.

Zuma Modified Maneuver as a Treatment to Geotropic Lateral Semicircular Canal Benign Paroxysmal Positional Vertigo.

Introduction Benign Paroxysmal Positional Vertigo (BPPV) is the most common vestibular disorder, resulting from detached otoliths that migrate to one of the semicircular canals - canalolithiasis - or one of the cupulas - cupulolithiasis. The present study is related to lateral canal BPPVs, which may be either geotropic or apogeotropic. The geotropic variant of lateral semicircular canal benign paroxysmal positional vertigo (LC-BPPV) is attributed to free floating particles in the posterior arm of the lateral semicircular canal. Objectives To verify the possibility of employing the Zuma repositioning maneuver, with a brief modification, as an alternative treatment for geotropic LC-BPPV. Methods Seven patients with geotropic LC-BPPV were enrolled and treated with the Zuma modified maneuver. Patients were reevaluated 1 hour after a single maneuver, to confirm the resolution of vertigo and positional nystagmus. Results All seven patients achieved immediate resolution of vertigo and positional nystagmus as measured 1 hour after the application of the maneuver. Conclusion The Zuma modified maneuver was effective for geotropic LC-BPPV after a single application. The use of the Zuma maneuver for both apogeotropic and geotropic LC-BPPV may simplify the treatment of these patients.

Zuma Modified Maneuver as a Treatment to Geotropic Lateral Semicircular Canal Benign Paroxysmal Positional Vertigo

Abstract Introduction Benign Paroxysmal Positional Vertigo (BPPV) is the most common vestibular disorder, resulting from detached otoliths that migrate to one of the semicircular canals - canalolithiasis - or one of the cupulas - cupulolithiasis. The present study is related to lateral canal BPPVs, which may be either geotropic or apogeotropic. The geotropic variant of lateral semicircular canal benign paroxysmal positional vertigo (LC-BPPV) is attributed to free floating particles in the posterior arm of the lateral semicircular canal. Objectives To verify the possibility of employing the Zuma repositioning maneuver, with a brief modification, as an alternative treatment for geotropic LC-BPPV. Methods Seven patients with geotropic LC-BPPV were enrolled and treated with the Zuma modified maneuver. Patients were reevaluated 1 hour after a single maneuver, to confirm the resolution of vertigo and positional nystagmus. Results All seven patients achieved immediate resolution of vertigo and positional nystagmus as measured 1 hour after the application of the maneuver. Conclusion The Zuma modified maneuver was effective for geotropic LC-BPPV after a single application. The use of the Zuma maneuver for both apogeotropic and geotropic LC-BPPV may simplify the treatment of these patients.

Corrective Saccades in Unilateral and Bilateral Vestibular Hypofunction During Slow Rotation Expressed by Visually Enhanced VOR and VOR Suppression: Role of the Cerebellum.

In clinical practice, the head impulse test paradigm (HIMP) and the suppression head impulse paradigm (SHIMP) stimulate high-frequency head movements so that the visual system is temporarily suppressed. The two tests could also be useful tools for vestibular assessment at low frequencies: VVOR (visually enhanced vestibulo-ocular reflex) and VORS (vestibulo-ocular reflex suppression). The aim of this study is to analyze the eye movements typically found during VVOR and VORS testing in patients with unilateral and bilateral vestibular hypofunction. Twenty patients with unilateral vestibular hypofunction, three patients with bilateral vestibular hypofunction, and ten patients with normal vestibular function (control group) were analyzed through VVOR and VORS testing with an Otometrics ICS Impulse system. During the VVOR test, patients with unilateral vestibular hypofunction exhibited corrective saccades to the same direction of the nystagmus fast phase toward the healthy side when the head rotates toward the affected side, while patients with bilateral vestibular hypofunction exhibited corrective saccades to the opposite side of head movements to each side. During the VORS test, patients with unilateral vestibular hypofunction seem to exhibit larger corrective saccades to the healthy side when the head was moved to this side, while patients with bilateral vestibular hypofunction did not exhibit corrective saccades during head movements to either side. Our data suggest that the VVOR and VORS tests yield the same diagnostic information as the HIMP and SHIMP tests in unilateral and bilateral vestibular hypofunction, and can contribute to the diagnosis of a peripheral vestibular loss as well as the affected side.

An Algorithm for the Diagnosis of Vestibular, Cerebellar, and Oculomotor Disorders Using a Systematized Clinical Bedside Examination.

The bedside examination associated with their clinical history remains the most critical means to accurately diagnose the cause for most of the signs and symptoms related to pathology of the cerebellum and vestibular system in patients presenting with dizziness and imbalance. This paper focuses on those critical bedside examinations, suggests when laboratory testing might be useful to confirm the clinical suspicion, and considers the shared neural circuitry within the visual and vestibular systems to offer an algorithmic approach in conducting the clinical bedside examination.

Management of Lateral Semicircular Canal Benign Paroxysmal Positional Vertigo.

Benign paroxysmal positional vertigo (BPPV) is the most common cause of peripheral vestibular vertigo. It is caused by free-floating otoconia moving freely in one of the semicircular canals (canalolithiasis) or by otoliths adhered to the cupula (cupulolithiasis). The posterior canal is the most common canal affected, followed by the lateral canal. Diagnosis of the side affected is critical for successful treatment; therefore, suppressing visual fixation is essential to examination of these patients' eye movement. On the basis of our experience, we have adopted the Zuma maneuver and the modified Zuma maneuver for both apogeotropic and geotropic variants of lateral canal BPPV. Knowledge of the anatomy and pathophysiologic mechanisms of the semicircular canals is essential for correct management of these patients. Hence, using a single maneuver and its modification may facilitate daily neurotological practice.

Neurotology: definitions and evidence-based therapies - Results of the I Brazilian Forum of Neurotology / Otoneurologia: definições e terapias baseadas em evidências - Resultados do I Fórum Brasileiro de Otoneurologia

Abstract Introduction: Neurotology is a rapidly expanding field of knowledge. The study of the vestibular system has advanced so much that even basic definitions, such as the meaning of vestibular symptoms, have only recently been standardized. Objective: To present a review of the main subjects of neurotology, including concepts, diagnosis and treatment of Neurotology, defining current scientific evidence to facilitate decision-making and to point out the most evidence-lacking areas to stimulate further new research. Methods: This text is the result of the I Brazilian Forum of Neurotology, which brought together the foremost Brazilian researchers in this area for a literature review. In all, there will be three review papers to be published. This first review will address definitions and therapies, the second one will address diagnostic tools, and the third will define the main diseases diagnoses. Each author performed a bibliographic search in the LILACS, SciELO, PubMed and MEDLINE databases on a given subject. The text was then submitted to the other Forum participants for a period of 30 days for analysis. A special chapter, on the definition of vestibular symptoms, was translated by an official translation service, and equally submitted to the other stages of the process. There was then a in-person meeting in which all the texts were orally presented, and there was a discussion among the participants to define a consensual text for each chapter. The consensual texts were then submitted to a final review by four professors of neurotology disciplines from three Brazilian universities and finally concluded. Based on the full text, available on the website of the Brazilian Association of Otorhinolaryngology and Cervical-Facial Surgery, this summary version was written as a review article. Result: The text presents the official translation into Portuguese of the definition of vestibular symptoms proposed by the Bárány Society and brings together the main scientific evidence for each of the main existing therapies for neurotological diseases. Conclusion: This text rationally grouped the main topics of knowledge regarding the definitions and therapies of Neurotology, allowing the reader a broad view of the approach of neurotological patients based on scientific evidence and national experience, which should assist them in clinical decision-making, and show the most evidence-lacking topics to stimulate further study.

Resumo Introdução: A otoneurologia é uma área de conhecimento que tem se expandido muito rapidamente. O estudo do sistema vestibular tem avançado tanto que mesmo definições básicas, como o significado dos sintomas vestibulares, foram apenas recentemente padronizadas. Objetivo: Apresentar uma revisão dos principais assuntos da otoneurologia, inclusive conceitos, diagnóstico e tratamento da otoneurologia, definir a evidência científica atual para facilitar a tomada de decisões e demonstrar as áreas mais carentes de evidência para estimular novas pesquisas. Método: Este texto é fruto do I Fórum Brasileiro de Otoneurologia, que reuniu os principais pesquisadores brasileiros dessa área para uma revisão da literatura. Serão feitos três trabalhos de revisão a serem publicados. Este primeiro abordou as definições e as terapias, o segundo abordará as ferramentas diagnósticas e o terceiro definirá os principais diagnósticos. Cada autor fez um levantamento bibliográfico na base de dados da Lilacs, SciELO, Pubmed e Medline de um determinado assunto. O seu texto foi então submetido aos demais participantes do Fórum por 30 dias para análise. Um capítulo especial, da definição dos sintomas vestibulares, foi traduzido por serviço de tradução oficial e igualmente submetido às demais etapas do processo. Houve então uma reunião presencial em que todos os textos foram apresentados oralmente e houve uma discussão entre os participantes para a definição de um texto consensual para cada capítulo. Os textos consensuais foram então submetidos a uma revisão final por quatro professores de otoneurologia de três universidades brasileiras e, por fim, finalizado. A partir do texto completo, publicado no site da Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial, foi escrita esta versão-resumo como artigo de revisão. Resultado: O texto apresenta a tradução oficial para o português da definição dos sintomas vestibulares propostos pela Barany Society e agrupa as principais evidências científicas para cada um das principais terapias existentes para as doenças otoneurológicas. Conclusão: Este texto agrupou de forma racional os principais tópicos de conhecimento a respeito das definições e terapias da otoneurologia, permite ao leitor uma visão ampla da abordagem dos pacientes otoneurológicos baseada em evidências científicas e experiência nacional, que deverá auxiliá-lo na tomada de decisões clínicas, e mostra os assuntos mais carentes de evidência para estimular novos estudos.

Neurotology: definitions and evidence-based therapies - Results of the I Brazilian Forum of Neurotology.

INTRODUCTION: Neurotology is a rapidly expanding field of knowledge. The study of the vestibular system has advanced so much that even basic definitions, such as the meaning of vestibular symptoms, have only recently been standardized. OBJECTIVE: To present a review of the main subjects of neurotology, including concepts, diagnosis and treatment of Neurotology, defining current scientific evidence to facilitate decision-making and to point out the most evidence-lacking areas to stimulate further new research. METHODS: This text is the result of the I Brazilian Forum of Neurotology, which brought together the foremost Brazilian researchers in this area for a literature review. In all, there will be three review papers to be published. This first review will address definitions and therapies, the second one will address diagnostic tools, and the third will define the main diseases diagnoses. Each author performed a bibliographic search in the LILACS, SciELO, PubMed and MEDLINE databases on a given subject. The text was then submitted to the other Forum participants for a period of 30 days for analysis. A special chapter, on the definition of vestibular symptoms, was translated by an official translation service, and equally submitted to the other stages of the process. There was then a in-person meeting in which all the texts were orally presented, and there was a discussion among the participants to define a consensual text for each chapter. The consensual texts were then submitted to a final review by four professors of neurotology disciplines from three Brazilian universities and finally concluded. Based on the full text, available on the website of the Brazilian Association of Otorhinolaryngology and Cervical-Facial Surgery, this summary version was written as a review article. RESULT: The text presents the official translation into Portuguese of the definition of vestibular symptoms proposed by the Bárány Society and brings together the main scientific evidence for each of the main existing therapies for neurotological diseases. CONCLUSION: This text rationally grouped the main topics of knowledge regarding the definitions and therapies of Neurotology, allowing the reader a broad view of the approach of neurotological patients based on scientific evidence and national experience, which should assist them in clinical decision-making, and show the most evidence-lacking topics to stimulate further study.

Apogeotropic variant of horizontal semicircular canal benign paroxysmal positional vertigo: Where are the particles?

The apogeotropic variant of horizontal semicircular canal benign paroxysmal positional vertigo (HC-BPPV) is attributed to free floating particles in the anterior arm of the lateral semicircular canal - particles attached to the cupula facing the canal or particles attached to the cupula facing the utricle. Zuma e Maia described a new treatment for both canalithiasis of the anterior arm of the horizontal semicircular canal (HC) and cupulolithiasis of the HC. Seventeen patients with apogeotropic HC-BPPV were enrolled and treated with Zuma's Maneuver. During the repositioning of the particles to the utricule, we observed the direction of the nystagmus evoked in each step of this maneuver in order to know where the otoliths were probably located. Eight patients were diagnosed with canalithiasis of the anterior arm, six patients with cupulolithiasis with the particles facing the canal and three patients with cupulolithiasis with the particles facing the utricle. Our data suggest that we can assume where the otoliths are probably located by observing the pattern of the nystagmus evoked in each step of the Zuma's Maneuver in patients with apogeotropic HC-BPPV.

Seasonality and solar radiation variation level in benign paroxysmal positional vertigo.

BACKGROUND: Several studies have shown that the incidence of benign paroxysmal positional vertigo (BPPV) presents seasonal variations and there is evidence that the variation in time is dependent on the patient's amount of vitamin D. OBJECTIVES: This is a retrospective study to verify if there is a correlation between the incidence of BPPV and the level of solar radiation, essential for the synthesis of vitamin D in the skin. MATERIAL AND METHODS: This study comprised 214 patients with BPPV seen from 2012 to 2017, in a city Latitude: -30.0277, Longitude: -51.2287 30° 1' 40″ South, 51° 13' 43″ West. The amounts of monthly solar radiation were analyzed in relation to the dates of their first consultations. Statistical tests were employed to verify the existence of a correlation between solar radiation and the incidence of the disease. RESULTS: The statistical analysis revealed a significant difference between the incidence of BPPV and the amount of radiation during the month of the diagnosis of the disease. There was also a significant statistical correlation with the climatic variation. CONCLUSION: More patients with benign paroxysmal positional vertigo (BPPV) are seen in consultation in the months with low solar radiation and in the autumn and winter seasons, in this geographic city.

Assessment of Pulmonary Function before and after Sinus Surgery in Lung Transplant Recipients

Abstract Introduction The association between sinus and lung diseases is well known. However, there are scarce studies regarding the effects of sinus surgery on pulmonary function in lung transplant recipients. The present study describes our experience with sinus surgery in lung transplant recipients with chronic rhinosinusitis. Objectives To assess the impact of sinus surgery for chronic rhinosinusitis on pulmonary function and on inpatient hospitalization days due to lower respiratory tract infection in lung transplant recipients. Methods A retrospective study conducted between 2006 and 2012 on a sample of lung transplant recipients undergoing sinus surgery for chronic rhinosinusitis. Pulmonary function, measured by forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1), as well as inpatient hospitalization days due to lower respiratory tract infection, were compared 6 months before and 6 months after sinus surgery. Results The FEV1 values increased significantly, and the inpatient hospitalization days due to bronchopneumonia decreased significantly 6 months after sinus surgery. The preoperative and postoperative median FEV1 values were 2.35 and 2.68 respectively (p = 0.0056). The median number of inpatient hospitalization days due to bronchopneumonia 6 months before and 6 months after surgery were 32.82 and 5.41 respectively (p = 0.0013). Conclusion In this sample of lung transplant recipients with chronic rhinosinusitis, sinus surgery led to an improvement in pulmonary function and a decrease in inpatient hospitalization days due to bronchopneumonia.

Assessment of Pulmonary Function before and after Sinus Surgery in Lung Transplant Recipients.

Introduction The association between sinus and lung diseases is well known. However, there are scarce studies regarding the effects of sinus surgery on pulmonary function in lung transplant recipients. The present study describes our experience with sinus surgery in lung transplant recipients with chronic rhinosinusitis. Objectives To assess the impact of sinus surgery for chronic rhinosinusitis on pulmonary function and on inpatient hospitalization days due to lower respiratory tract infection in lung transplant recipients. Methods A retrospective study conducted between 2006 and 2012 on a sample of lung transplant recipients undergoing sinus surgery for chronic rhinosinusitis. Pulmonary function, measured by forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1), as well as inpatient hospitalization days due to lower respiratory tract infection, were compared 6 months before and 6 months after sinus surgery. Results The FEV1 values increased significantly, and the inpatient hospitalization days due to bronchopneumonia decreased significantly 6 months after sinus surgery. The preoperative and postoperative median FEV1 values were 2.35 and 2.68 respectively ( p = 0.0056 ). The median number of inpatient hospitalization days due to bronchopneumonia 6 months before and 6 months after surgery were 32.82 and 5.41 respectively ( p = 0.0013 ). Conclusion In this sample of lung transplant recipients with chronic rhinosinusitis, sinus surgery led to an improvement in pulmonary function and a decrease in inpatient hospitalization days due to bronchopneumonia.

Hearing preservation using topical dexamethasone alone and associated with hyaluronic acid in cochlear implantation.

CONCLUSION: Topical dexamethasone associated with hyaluronic acid in cochlear implant surgery demonstrated a statistically significant difference in the preservation of low-frequency thresholds when compared with topical dexamethasone alone and a control group. Topical dexamethasone alone was not superior in hearing preservation when compared to the control group. OBJECTIVE: To compare the effects of topical dexamethasone alone and associated with hyaluronic acid intraoperatively in hearing preservation in cochlear implantation. METHODS: Eighteen severely to profoundly hearing-impaired adult patients with measurable hearing were divided into three groups preoperatively: cochlear implantation as a control group (group 1), cochlear implantation using topical dexamethasone intraoperatively (group 2), and cochlear implantation using topical dexamethasone associated with hyaluronic acid intraoperatively (group 3). Preimplant and postimplant low-frequency pure-tone averages (PTAs) were calculated from unaided audiograms at 125, 250, and 500 Hz. RESULTS: The mean changes in the low-frequency PTA comparing postoperative against preoperative thresholds were 28.03 ± 6.77 dB in group 1, 30 ± 14.53 dB in group 2, and 7.23 ± 6.12 dB in group 3. There was statistical difference when comparing group 3 with groups 1 and 2 using one-way ANOVA (p = 0.002) followed by Scheffé post hoc test.

Evaluation of residual hearing in cochlear implants candidates using auditory steady-state response.

CONCLUSION: The correlations between behavioral and auditory steady-state response (ASSR) thresholds were significant at 500, 1000, 2000, and 4000 Hz. ASSR presented high sensitivity and specificity in the detection of residual hearing in cochlear implant candidates when compared with warble-tone audiometry. OBJECTIVES: To assess residual hearing in cochlear implant candidates by comparing the electrophysiological thresholds obtained in dichotic single-frequency ASSR with behavioral thresholds at 500, 1000, 2000, and 4000 Hz. METHODS: This was a comparative study between ASSR and warble-tone audiometry thresholds in 40 cochlear implant candidates (80 ears) before cochlear implantation with bilateral severe-to-profound sensorineural hearing loss. RESULTS: Thresholds were obtained in 62.5% of all frequencies evaluated in warble-tone audiometry and in 63.1% in the ASSR. ASSR sensitivity was 96% and specificity was 91.6%. Mean differences between behavioral and ASSR thresholds did not reach significance at any frequencies. Strong correlations between behavioral and ASSR thresholds were observed in 500, 1000, and 2000 Hz and moderate in 4000 Hz, with correlation coefficients varying from 0.65 to 0.81. On 90% of occasions, ASSR thresholds were acquired within 10 dB of behavioral thresholds.

Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects.

INTRODUCTION: Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. AIM: Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. MATERIALS AND METHODS: In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. RESULTS: The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. CONCLUSION: ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation.

Estudo comparativo entre audiometria tonal limiar e resposta auditiva de estado estavel em normouvintes / Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects

Introdução: As respostas auditivas de estado estável permitem avaliar de forma objetiva limiares auditivos frequência-específica. A audiometria tonal é o exame padrão-ouro; no entanto, nem sempre pode ser conclusiva, principalmente em crianças e adultos não colaborativos. Objetivo: Comparar os limiares auditivos da RAEE aos da audiometria tonal em indivíduos com audição normal. Materiais e métodos: Foram incluídos neste estudo prospectivo de corte transversal 26 adultos (52 orelhas), de ambos os gêneros, com audiometria normal e sem queixas otológicas. Os pacientes foram submetidos a anamnese, otomicroscopia, audiometria e imitanciometria. A seguir, realizou-se avaliação de respostas auditivas de estado estável. Os resultados obtidos foram analisados estatisticamente e comparados entre si. Resultados: A diferença entre os limiares (em dB NA) obtidos em ambos os exames para cada frequência testada foi de 7,12 dB para 500 Hz; 7,6 dB para 1000 Hz; 8,27 dB para 2000 Hz e 9,71 dB para 4000 Hz, com limiares mais elevados na RAEE, em todas as frequências. Não houve diferença estatística entre as médias para cada frequência testada. Conclusão: Os limiares obtidos na RAEE foram comparáveis aos da audiometria tonal em indivíduos normouvintes; entretanto, não deve ser usado como único método de avaliação auditiva. .

Introduction: Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. Aim: Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. Materials and methods: In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. Results: The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. Conclusion: ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation. .