Camila Maia Rabelo

Sensitividade e especificidade do potencial de média latência

The Middle Latency Response (MLR) is a neuroelectrical response that can be recorded in the far field using scalp electrode. Nowadays it is suppose to be one of the best evoked potential for evaluate lesion or dysfunction of the central auditory nervous system. The MLR waves occur between 10 and 80 msec (ms) after the stimulus onset. The Pa is the most reliable because it is the most visible and robust of this potential. Because of the big variability of the amplitude and the latency of the MLR waves it is not yet largely used in the clinical set. AIM: The purpose of this study was to establish the sensitivity and specificity of the MLR waves. STUDY DESIGN: Case-control. MATERIAL AND METHOD: Individuals between 15 and 55 years old with lesion of the central auditory nervous system, with auditory processing disorders and normal one (control group) were evaluated using the MLR. RESULTS: The results showed that the amplitude difference of 30% held the better results, for the electrode as well as the ear effect. The ear effect was more efficient in detecting auditory processing disorder while the electrode effect was better for detecting the lesion.

Development and analysis of a low-cost screening tool to identify and classify hearing loss in children: a proposal for developing countries

OBJECTIVES: A lack of attention has been given to hearing health in primary care in developing countries. A strategy involving low-cost screening tools may fill the current gap in hearing health care provided to children. Therefore, it is necessary to establish and adopt lower-cost procedures that are accessible to underserved areas that lack other physical or human resources that would enable the identification of groups at risk for hearing loss. The aim of this study was to develop and analyze the efficacy of a low-cost screening tool to identify and classify hearing loss in children. METHODS: A total of 214 2-to-10 year-old children participated in this study. The study was conducted by providing a questionnaire to the parents and comparing the answers with the results of a complete audiological assessment. Receiver operating characteristic (ROC) curves were constructed, and discriminant analysis techniques were used to classify each child based on the total score. RESULTS: We found conductive hearing loss in 39.3% of children, sensorineural hearing loss in 7.4% and normal hearing in 53.3%. The discriminant analysis technique provided the following classification rule for the total score on the questionnaire: 0 to 4 points – normal hearing; 5 to 7 points – conductive hearing loss; over 7 points – sensorineural hearing loss. CONCLUSION: Our results suggest that the questionnaire could be used as a screening tool to classify children with normal hearing or hearing loss and according to the type of hearing loss based on the total questionnaire score.

P300 with verbal and nonverbal stimuli in normal hearing adults

UNLABELLED The P300 results from focusing attention on rare stimuli in the midst of other frequent stimuli; it tests recent attention and memory, both of which depend on discriminating among verbal or nonverbal stimuli. AIM To compare the P300 with verbal and nonverbal stimuli in normal-hearing adults. MATERIAL AND METHOD A prospective study was made of 15 male subjects aged from 22 to 55, with no hearing complaints. The subjects underwent short and long latency (P300) auditory evoked potentials with verbal and non-verbal stimuli. RESULTS The mean P300 latency with verbal stimuli was significantly higher than the P300 with nonverbal stimuli. The P300 amplitudes were significantly lower for verbal compared with non-verbal stimuli. CONCLUSION There were no differences between ears with respect to P300 latencies and amplitudes for both non-verbal and verbal stimuli. Latencies were higher with verbal stimuli; amplitudes had lower values.

Audiological and electrophysiological assessment of professional pop/rock musicians.

In the present study, we evaluated peripheral and central auditory pathways in professional musicians (with and without hearing loss) compared to non-musicians. The goal was to verify if music exposure could affect auditory pathways as a whole. This is a prospective study that compared the results obtained between three groups (musicians with and without hearing loss and non-musicians). Thirty-two male individuals participated and they were assessed by: Immittance measurements, pure-tone air conduction thresholds at all frequencies from 0.25 to 20 kHz, Transient Evoked Otoacoustic Emissions, Auditory Brainstem Response (ABR), and Cognitive Potential. The musicians showed worse hearing thresholds in both conventional and high frequency audiometry when compared to the non-musicians; the mean amplitude of Transient Evoked Otoacoustic Emissions was smaller in the musicians group, but the mean latencies of Auditory Brainstem Response and Cognitive Potential were diminished in the musicians when compared to the non-musicians. Our findings suggest that the population of musicians is at risk for developing music-induced hearing loss. However, the electrophysiological evaluation showed that latency waves of ABR and P300 were diminished in musicians, which may suggest that the auditory training to which these musicians are exposed acts as a facilitator of the acoustic signal transmission to the cortex.

Time-compressed speech test in Brazilian Portuguese

INTRODUCTION The time-compressed speech test has existed since the 1970s. It is sensitive for evaluating auditory closure. However, it is not used in Brazil because until recently, it had not been developed in Portuguese. PURPOSE To develop a compressed speech test in Portuguese, to apply it to normal-hearing adults, and to verify which of the compressed lists (50%, 60%, or 70%) is the most appropriate to be part of a set of auditory processing tests. METHODS 144 normal-hearing adults, distributed homogeneously between both genders, were assessed. The compressed speech tests were applied using monosyllables and disyllables according to 8 previously established sequences, and the results were compared with respect to the initial ear, to the order of presentation, and to the kind of test. RESULTS There were no significant differences between ears. The 50%, 60% and 70% presentation order produced a better average of correct responses than the 70%, 60% and 50% one. There was a significant difference (P <.001) between the results of the tests comprising lists of monosyllables compared to those comprising disyllables. In both tests (with monosyllables and disyllables) the average of correct responses decreased as the compression increased. CONCLUSION The monosyllabic and disyllabic lists with 60% compression appeared to be more stable than the others, with the average of correct responses around 90%.

O teste Gaps-in-Noise: limiares de detecção de gap em crianças de 9 anos com audição normal

PURPOSE: To establish the standard criteria for the Gaps-in-Noise (GIN) test in 9-year-old normal-hearing children; to obtain the mean gap detection thresholds; and to verify the influence of the variables gender and ear on the gap detection thresholds. METHODS: Forty normal-hearing individuals, 20 male and 20 female, with ages ranging from 9 years to 9 years and 11 months, were evaluated. The procedures performed were: anamnesis, audiological evaluation, acoustic immittance measures (tympanometry and acoustic reflex), Dichotic Digits Test, and GIN test. The results obtained were statistically analyzed. RESULTS: The results revealed similar performance of right and left ears in the population studied. There was also no difference regarding the variable gender. In the subjects evaluated, the mean gap detection thresholds were 4.4 ms for the right ear, and 4.2 ms for the left ear. CONCLUSION: The values obtained for right and left ear, as well as their standard deviations, can be used as standard criteria for 9-year-old children, regardless of ear or gender.

Original ArticleP300 with verbal and nonverbal stimuli in normal hearing adults

UNLABELLED The P300 results from focusing attention on rare stimuli in the midst of other frequent stimuli; it tests recent attention and memory, both of which depend on discriminating among verbal or nonverbal stimuli. AIM To compare the P300 with verbal and nonverbal stimuli in normal-hearing adults. MATERIAL AND METHOD A prospective study was made of 15 male subjects aged from 22 to 55, with no hearing complaints. The subjects underwent short and long latency (P300) auditory evoked potentials with verbal and non-verbal stimuli. RESULTS The mean P300 latency with verbal stimuli was significantly higher than the P300 with nonverbal stimuli. The P300 amplitudes were significantly lower for verbal compared with non-verbal stimuli. CONCLUSION There were no differences between ears with respect to P300 latencies and amplitudes for both non-verbal and verbal stimuli. Latencies were higher with verbal stimuli; amplitudes had lower values.

Impact of Educational Level on Performance on Auditory Processing Tests

Research has demonstrated that a higher level of education is associated with better performance on cognitive tests among middle-aged and elderly people. However, the effects of education on auditory processing skills have not yet been evaluated. Previous demonstrations of sensory-cognitive interactions in the aging process indicate the potential importance of this topic. Therefore, the primary purpose of this study was to investigate the performance of middle-aged and elderly people with different levels of formal education on auditory processing tests. A total of 177 adults with no evidence of cognitive, psychological or neurological conditions took part in the research. The participants completed a series of auditory assessments, including dichotic digit, frequency pattern and speech-in-noise tests. A working memory test was also performed to investigate the extent to which auditory processing and cognitive performance were associated. The results demonstrated positive but weak correlations between years of schooling and performance on all of the tests applied. The factor “years of schooling” was also one of the best predictors of frequency pattern and speech-in-noise test performance. Additionally, performance on the working memory, frequency pattern and dichotic digit tests was also correlated, suggesting that the influence of educational level on auditory processing performance might be associated with the cognitive demand of the auditory processing tests rather than auditory sensory aspects itself. Longitudinal research is required to investigate the causal relationship between educational level and auditory processing skills.

Diabetes mellitus and sensorineural hearing loss: is there an association? Baseline of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

OBJECTIVES: Although several studies have investigated the effects of diabetes on hearing loss, the relationship between these two conditions remains unclear. Some studies have suggested that diabetes may cause sensorineural hearing loss, whereas others have failed to find an association. The biggest challenge in investigating the association between diabetes and hearing loss is the presence of confounding variables and the complexity of the auditory system. Our study investigated the association between diabetes and sensorineural hearing loss. We evaluated the influence of time from diabetes diagnosis on this association after controlling for age, gender, and hypertension diagnosis and excluding those subjects with exposure to noise. METHODS: This cross-sectional study evaluated 901 adult and elderly Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) participants from São Paulo, Brazil who underwent audiometry testing as part of ELSA-Brasil’s baseline assessment. RESULTS: Hearing thresholds and speech test results were significantly worse in the group with diabetes than in the group without diabetes. However, no significant differences were found between participants with and without diabetes after adjusting for age, gender, and the presence of hypertension. Hearing thresholds were not affected by occupational noise exposure in the groups with and without diabetes. In addition, no association between the duration of diabetes and hearing thresholds was observed after adjusting for age, gender, and hypertension. CONCLUSION: We found no association between the duration of diabetes and worse hearing thresholds after models were adjusted for age, gender, and the presence of hypertension.

O Potencial Evocado Auditivo com estímulo de fala pode ser uma ferramenta útil na prática clínica

Purpose : To discuss the clinical applicability of the speech-evoked Auditory Brainstem Response (speech-evoked ABR) to help identifying auditory processing disorders. Methods : We analyzed the records of 27 children and adolescents, aged between seven and 15, who presented abnormal speech-evoked ABR. Then, the data from the behavioral auditory processing evaluation of these individuals were surveyed. Results : It was observed that, among the 27 children with abnormal speech-evoked ABR, 23 also had auditory processing disorders. Therefore, from this sample, an 85.15% probability of observing abnormal behavioral assessment of auditory processing in a child who presented abnormal speech-evoked ABR was obtained. Conclusion : It is argued that the speech-evoked ABR can be used in clinical practice as an important aid tool in the diagnosis of auditory processing disorder, because, in this study, an abnormal speech-evoked ABR usually represented a deficit in the results of behavioral assessment of auditory processing. Thus, it can be used to obtain information about the perception of speech sounds in children under seven years or with challenging behavioral assessment.PURPOSE To discuss the clinical applicability of the speech-evoked Auditory Brainstem Response (speech-evoked ABR) to help identifying auditory processing disorders. METHODS We analyzed the records of 27 children and adolescents, aged between seven and 15, who presented abnormal speech-evoked ABR. Then, the data from the behavioral auditory processing evaluation of these individuals were surveyed. RESULTS It was observed that, among the 27 children with abnormal speech-evoked ABR, 23 also had auditory processing disorders. Therefore, from this sample, an 85.15% probability of observing abnormal behavioral assessment of auditory processing in a child who presented abnormal speech-evoked ABR was obtained. CONCLUSION It is argued that the speech-evoked ABR can be used in clinical practice as an important aid tool in the diagnosis of auditory processing disorder, because, in this study, an abnormal speech-evoked ABR usually represented a deficit in the results of behavioral assessment of auditory processing. Thus, it can be used to obtain information about the perception of speech sounds in children under seven years or with challenging behavioral assessment.