Frequency-Following Response with Speech Stimulus: Comparison between Two Methods of Stimulation

Introduction: Frequency-following response with speech stimulus (FFR-speech) is a subcortical potential that satisfactorily evaluates the processing of verbal information. However, there still are differences in the literature regarding its analysis and stimulation protocol. Objective: To compare two stimulation protocols for the capture of FFR-speech, to identify the percentage of occurrence of the waves among them and to compare it with the specialized literature, as well as to describe the interpeaks of its waves. Method: Considering the eligibility criteria, the sample consisted of 30 normal-hearing adults, with no complaints of speech comprehension. All of them were submitted to a basic audiological evaluation, to brainstem auditory evoked potential with click stimulus, and to FFR-speech. In the latter, 2 types of stimulation were performed, 3 series of 1,000 sweeps, and 2 series of 3,000 sweeps, for subsequent analysis of the resulting wave, in which we tried to mark the peak V followed by valleys A, C, D, E, F, and O. Results: Differences in latency and interpeaks were not found between the protocols. In general, a higher occurrence of waves in the stimulation of 2 series of 3,000 sweeps was observed, but only the A valley presented a significant difference. When the values of the waves were compared with the literature, the V and A waves showed fewer occurrences in the present study. Conclusion: The protocol of 2 series of 3,000 sweeps was better for FFR-speech in the studied equipment, considering the higher occurrence of waves, even though it is inferior to the specialized literature. Furthermore, it was possible to describe interpeak values and to observe no difference between the studied protocols (AU)

Limiares de audibilidade de altas frequências em indivíduos adultos normo-ouvintes / High-frequency auditory thresholds in normal hearing adults

RESUMO Objetivo Avaliar os limiares auditivos nas altas frequências, buscando comparar as respostas entre as orelhas, verificar a correlação do nível de audibilidade com o aumento da idade e analisar as respostas por frequência para adultos normo-ouvintes. Método Este estudo foi prospectivo, quantitativo e transversal, com amostra por conveniência. Fizeram parte da amostra 60 sujeitos, com idade entre 18 e 58 anos, média de idade de 25,8 anos, com limiares auditivos dentro dos padrões de normalidade de 250 a 8000 Hz e normalidade de resultados nas medidas de imitância acústica. Para a pesquisa das altas frequências foi utilizado o equipamento de modelo AS10 HF da marca Interacoustics com fones de ouvido do tipo KOSS R/80 e com limiares expressos em dBNPS. Resultados Quanto aos limiares de audibilidade há um aumento para a orelha direita, com significância estatística em 10, 11 e 14 kHz e uma tendência à significância em 13 kHz, assim como a partir da frequência de 14 kHz há um aumento progressivo diretamente proporcional à frequência bilateralmente e quanto maior for a idade dos indivíduos, maiores serão os limiares para todas as frequências. Conclusão Os limiares de audibilidade de altas frequências tornam-se maiores com um aumento progressivo proporcional ao avanço de frequência e idade de indivíduos normo-ouvintes com valores mais elevados para a orelha direita.

ABSTRACT Purpose Evaluate high-frequency auditory thresholds, seeking to compare responses between the ears, to verify the correlation between hearing level and aging and analyze frequency responses in normal hearing adults. Methods This is a prospective, quantitative, transversal study conducted with a convenience sample. Study participants were 60 individuals aged 18 to 58 years (mean=25.82) with auditory thresholds within normality standards (250-8000 Hz) and normal results in acoustic immittance measurements. High-frequency pure-tone hearing thresholds were determined using an Interacoustics AS10HF audiometer with electrodynamic high-fidelity KOSS R/80 headphones, with thresholds expressed in dBNPS. Results Hearing thresholds showed an increase for the right ear with statistical significance at the 10, 11 and 14 kHz frequencies and a tendency to significance at 13 kHz. As of the 14 kHz frequency, a progressive increase directly proportional to the frequency was observed bilaterally, with the thresholds increasing proportionally to age advancement for all frequencies. Conclusion High-frequency auditory thresholds progressively increase proportionally to frequency and age advancement in normal hearing individuals, with higher values ​​for the right ear.