ABSTRACT Purpose: to investigate the frequency-following response (FFR) for sustained neural activity. Methods: 39 individuals, aged between 20 to 47 months old were divided into 2 groups: (i) 20 individuals without prenatal exposure to the congenital Zika syndrome (CZS) or hydrocephaly, normal development, no risk factors for hearing loss or syndromic hearing impairment and (ii) 19 individuals diagnosed with CZS and microcephaly - based on imaging studies linked to the clinical presentation of the condition. All participants exhibited normal click-ABR tests. FFR waveforms were documented using the /da/ syllable employing the Navigator Pro. The statistical analysis used was ANOVA (p-value <0.05). Results: no distinctions were observed concerning the variables of group, age, or gender with respect to FFR latency values, except for an interaction between gender and group for latency values associated with waves V and F. Children with CZS and microcephaly showed a difference for latency values in wave V for both males and females, when compared to the control group. Conclusion: children presented with CZS and microcephaly showed higher average latencies for waves V, A, C, D and F (male) compared to the control group, whereas, in waves E, F (female) and O they showed higher values in the control group.

Abstract Introduction Musicians have an advantage over non-musicians in detecting, perceiving, and processing nonverbal (i.e., environmental sounds, tones and others) and verbal sounds (i.e., consonant, vowel, phrases and others) as well as instrumental sounds. In contrast to the high skill of musicians, there is another group of people who are tone-deaf and have difficulty in distinguishing musical sounds or singing in tune. These sounds can originate in different ways, such as a musical instrument, orchestra, or the human voice. Objectives The objective of the present work is to study frequency-following responses (FFRs) in individuals who can sing in-tune and those who sing off-tune. Methods Electrophysiological responses were recorded in 37 individuals divided in two groups: (i) control group (CG) with professional musicians, and (ii) experimental group (EG) with non-musicians. Results There was homogeneity between the two groups regarding age and gender. The CG had more homogeneous responses in the latency of the FFRs waves when responses between the right and left ears were compared to those of the EG. Conclusions This study showed that monaural stimulation (right or left) in an FFR test is useful for demonstrating impairment of speech perception in individuals who sing off tune. The response of the left ear appears to present more subtlety and reliability when identifying the coding of speech sound in individuals who sing off tune.

ABSTRACT Purpose: to compare the Auditory Middle Latency Response in adults, one group with and another group without altered auditory skills. In addition, the aim was to compare cut-off values of 30% and 50% for the Ear Effect in terms of sensitivity and specificity. Methods: the sample comprised 32 individuals of both genders with no hearing loss who were divided into Group 1 (16 individuals with no alterations in auditory skills) and Group 2 (16 individuals with alterations in auditory skills). All participants received an audiological evaluation and measurement of Brainstem and Auditory Middle Latency Potentials. Results: when Group 1 and Group 2 were compared, a statistically significant difference was only observed in Na and Pa amplitude of waves A1C3 and A2C3. In the analysis of sensitivity and specificity of the Auditory Middle Latency Response, a cut-off value of 50% gave a better balance between sensitivity and specificity. Conclusion: adults presented with altered auditory abilities had smaller response amplitudes in the Na and Pa components of the waves generated in the left hemisphere. A cut-off value of 50% gave a better discrimination of the Ear Effect for identifying subjects with altered auditory skills.

RESUMO Objetivo: comparar a latência e a amplitude dos componentes Na, Pa, Nb e Pb do Potencial Evocado Auditivo de Média Latência em adultos com e sem alterações em habilidades auditivas, bem como analisar a sensibilidade e a especificidade dos valores de corte de 30% e 50% para o Efeito de Orelha. Métodos: compuseram a amostra 32 indivíduos de ambos os sexos e sem perda auditiva, sendo subdivididos em Grupo 1 (16 indivíduos sem alterações em habilidades auditivas) e Grupo 2 (16 indivíduos com alterações em habilidades auditivas). Todos os participantes foram submetidos a uma avaliação audiológica e aos Potenciais Evocados Auditivos de Tronco Encefálico de Média Latência. O teste ANOVA foi utilizado na análise dos dados, considerando significantes os valores de p menores ou iguais a 0,05. Resultados: foi observada diferença estatisticamente significante apenas na amplitude de Na e Pa, quando Grupo 1 e Grupo 2 foram comparados. Esta diferença foi observada nas ondas A1C3 e A2C3. Na análise de sensibilidade e especificidade do Potencial Evocado Auditivo de Média Latência, observou-se que o valor de corte de 50% apresentou um melhor equilíbrio entre os critérios de sensibilidade e especificidade. Conclusão: os indivíduos adultos com alterações nas habilidades auditivas apresentaram menor amplitude de resposta nos componentes Na e Pa das ondas geradas no hemisfério esquerdo. O valor de corte de 50% apresentou um melhor equilíbrio na análise do Efeito de Orelha para a contribuição no diagnóstico de alterações de habilidades auditivas.

RESUMO Objetivo: comparar a latência e a amplitude do Frequency-Following Response e do Potencial Evocado Auditivo de Média Latência em indivíduos típicos e com alterações das habilidades auditivas, assim como investigar a sensibilidade e especificidade de ambas as avaliações frente ao processamento auditivo central. Métodos: 32 indivíduos de ambos os sexos foram distribuídos em Grupo 1 (sem alterações de habilidades auditivas) e Grupo 2 (com alteração em habilidades auditivas). Os grupos foram divididos de acordo com testes comportamentais do processamento auditivo central. Os indivíduos de ambos os grupos foram submetidos aos potenciais evocados auditivos. O teste T de Student foi utilizado para a análise, considerando 5% de significância. Resultados: no Grupo 2, V e A apresentaram maior latência e menor amplitude e slope. O Grupo 2 também apresentou menores amplitudes de Na e Pa nas ondas A1C3 e A2C3. O Frequency-Following Response apresentou 93% de sensibilidade e especificidade, enquanto o Potencial Evocado Auditivo de Média Latência apresentou 87% de sensibilidade e 93% de especificidade. Conclusão: os indivíduos com alteração das habilidades auditivas apresentaram maior latência e menor amplitude de resposta no Frequency Following Response e Potencial Evocado Auditivo de Média Latência em relação aos indivíduos típicos. O Frequency-Following Response apresentou melhor equilíbrio de sensibilidade e especificidade.

ABSTRACT Purpose: to compare the latency and amplitude of the Frequency-Following Response and the Auditory Middle Latency Response in typical individuals and those with altered auditory abilities, as well as to investigate the sensitivity and specificity of both assessments in relation to central auditory processing. Methods: 32 individuals of both sexes were distributed into Group 1 (without altered auditory abilities) and Group 2 (with altered auditory abilities). The groups were divided according to behavioral tests of central auditory processing. Individuals in both groups underwent auditory evoked potentials. Student’s t-test was used for analysis, considering a 5% significance. Results: in Group 2, V and A had higher latency and lower amplitude and slope. Group 2 also had lower Na and Pa amplitudes in waves A1C3 and A2C3. The Frequency-Following Response showed 93% sensitivity and specificity, while the Auditory Middle Latency Response showed 87% sensitivity and 93% specificity. Conclusion: the individuals presented with altered hearing abilities showed higher latency and lower response amplitude in the Frequency Following Response and Auditory Middle Latency Response compared to typical individuals. The Frequency- Following Response showed a better balance of sensitivity and specificity.