Sheila Jacques Oppitz

Auditory Evoked Potentials with Different Speech Stimuli: a Comparison and Standardization of Values

Introduction Long Latency Auditory Evoked Potentials (LLAEP) with speech sounds has been the subject of research, as these stimuli would be ideal to check individualś detection and discrimination. Objective The objective of this study is to compare and describe the values of latency and amplitude of cortical potentials for speech stimuli in adults with normal hearing. Methods The sample population included 30 normal hearing individuals aged between 18 and 32 years old with ontological disease and auditory processing. All participants underwent LLAEP search using pairs of speech stimuli (/ba/ x /ga/, /ba/ x /da/, and /ba/ x /di/. The authors studied the LLAEP using binaural stimuli at an intensity of 75dBNPS. In total, they used 300 stimuli were used (∼60 rare and 240 frequent) to obtain the LLAEP. Individuals received guidance to count the rare stimuli. The authors analyzed latencies of potential P1, N1, P2, N2, and P300, as well as the ampleness of P300. Results The mean age of the group was approximately 23 years. The averages of cortical potentials vary according to different speech stimuli. The N2 latency was greater for /ba/ x /di/ and P300 latency was greater for /ba/ x /ga/. Considering the overall average amplitude, it ranged from 5.35 and 7.35uV for different speech stimuli. Conclusion It was possible to obtain the values of latency and amplitude for different speech stimuli. Furthermore, the N2 component showed higher latency with the / ba / x / di / stimulus and P300 for /ba/ x / ga /.

Long-latency auditory evoked potentials with verbal and nonverbal stimuli,

INTRODUCTION Long-latency auditory evoked potentials represent the cortical activity related to attention, memory, and auditory discrimination skills. Acoustic signal processing occurs differently between verbal and nonverbal stimuli, influencing the latency and amplitude patterns. OBJECTIVE To describe the latencies of the cortical potentials P1, N1, P2, N2, and P3, as well as P3 amplitude, with different speech stimuli and tone bursts, and to classify them in the presence and absence of these data. METHODS A total of 30 subjects with normal hearing were assessed, aged 18-32 years old, matched by gender. Nonverbal stimuli were used (tone burst; 1000Hz - frequent and 4000Hz - rare); and verbal (/ba/ - frequent; /ga/, /da/, and /di/ - rare). RESULTS Considering the component N2 for tone burst, the lowest latency found was 217.45ms for the BA/DI stimulus; the highest latency found was 256.5ms. For the P3 component, the shortest latency with tone burst stimuli was 298.7 with BA/GA stimuli, the highest, was 340ms. For the P3 amplitude, there was no statistically significant difference among the different stimuli. For latencies of components P1, N1, P2, N2, P3, there were no statistical differences among them, regardless of the stimuli used. CONCLUSION There was a difference in the latency of potentials N2 and P3 among the stimuli employed but no difference was observed for the P3 amplitude.

Potencial evocado auditivo de longa latência: diferenças na forma de contagem do estímulo raro

Purpose: identifying if there are differences in the findings of Long Latency Auditory Evoked Potencial for latency and amplitude in different ways of counting the rare stimulus, being mentally counting or marking on paper (without memorizing). Methods: this study was prospective and transversal. The sample consisted of convenience and comprised by 49 subjects, including 29 females and 20 males.The following procedures were performed: Visual inspection of the external auditory canal, pure tone audiometry, acoustic immittance measures and long latency auditory evoked potentials, which was performed twice, one after the other, with individuals paying attention to the rare stimulus, always starting counting mentally and after marking on paper. Results: there were significant differences between the ears to the P1, P2 latencies and amplitude of N1 for the method of marking on paper and the amplitude of P2 in both methods but with all values within the range normality. In addition, a statistically significant difference was also evident when comparing genders, being found larger latency values of P2 and N2 for males in both counting methods of the rare stimuli. The amplitude of P1, P2 and P3 was lower in males in different ways to count, being in P2 the only difference in the method counting mentally. When comparing the methods, there was a statistically significant difference only to the latency of P2 which was higher values for the method of marking on paper. Conclusion: there were no differences for the latencies and amplitudes of the long latency potentials in comparison of the rare stimulus score (counting mentally and marking on paper) for almost all potentials except for P2 potential regarding to amplitude and latency.

Comparação da aquisição de /k/ e /g/ e das sequências fonéticas [kw] e [gw] no pb - variáveis intervenientes e status fonológico

PURPOSE: to analyze and to compare the acquisition of the phonetic sequences [kw] and [gw] and of the plosives /k/ and /g/ by children with typical speech development, considering the intervening linguistic and extralinguistic variables.METHODS: the amount of analyzed words was 3193, after 213 interviews with children who present typical phonological development. The Phonological Assessment of Child was used and all words which contain the phonetic sequences [kw] e [gw] and the phonemes /k/ e /g/ were selected. The analyzed dependent variables were: correct and incorrect production of the referred phonemes. The intervening variables were: sex, age, tonicity, number of syllables in the word, preceding syllabic context, following syllabic context, position in the word, sonority and segment complexity. The statistical program VARBRUL was used with significance level of 5%.RESULTS:the selected variables for the correct production of [kw] e [gw] were age and position in the word. To the production of /k/ and /g/, the variables were sex, age, preceding syllabic context, following syllabic context and sonority. In the analysis of all words which were the corpus of this research, the statistic program selected the complexity of the segment as relevant in the acquisition of the analyzed segments. The highest probability of correct production was found for the phonemes /k/ and /g/.CONCLUSION: the fact that different variables are significant for the acquisition of /k,g/ and of [kw, gw] showed a reason for different children’s phonological therapy organization, regarding the mentioned sounds. It seems that the sequences [kw] and [gw] may be considered as complex segments of Brazilian Portuguese, because the complexity of the segment was selected as statistically significant in the studied corpus.

Limiares de audibilidade de altas frequências em indivíduos adultos normo-ouvintes

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.

Resolução temporal e potenciais corticais em diferentes níveis de proficiência da língua inglesa

Purpose: to investigate and compare hearing abilities in normal hearing bilingual students, at different levels of English proficiency (basic, intermediate and advanced), using behavioral testing and electrophysiological testing. Methods: this study is descriptive, quantitative and transversal. The sample consisted of 60 subjects (language schools students at different English proficiency levels: 20 at advanced level (AG); 20 at intermediate level (IG); 20 at basic level (BG)) with normal hearing and no complaints about auditory processing abilities, aged 18-35 years. They were subjected to behavioral test: Random Gap Detection Test (RGDT) that assesses ability of temporal resolution; and electrophysiological test Long Latency Auditory Evoked Potential (LLAEP) with verbal stimuli (syllables /ba/ - frequent stimulus and /di/ - rare stimulus) evaluating memory, attention and auditory discrimination. Results: it was noticed a statistically significant difference between ears for: BG, to amplitude of N1 and P2, with higher values for left ear; IG to amplitude of P1, N1 and P2, with higher values for left ear; AG to latency of N1, with higher values for left ear, and amplitudes of components P2, N2 and P3, with higher values for left ear. Between groups, RGDT showed lower values of AG, and latency of N1 component, with higher values for BG. Conclusion: there were significant differences in temporal resolution ability, better for students in advanced level of English and also to the latency of evoked cortical N1 with higher values for students at a basic level.

Auditory evoked potential P300 in adults: reference values

ABSTRACT Objective To establish reference intervals for cognitive potential P300 latency using tone burst stimuli. Methods This study involved 28 participants aged between 18 and 59 years. P300 recordings were performed using a two-channel device (Masbe, Contronic). Electrode placement was as follows: Fpz (ground electrode), Cz (active electrode), M1 and M2 (reference electrodes). Intensity corresponded to 80 dB HL and frequent and rare stimulus frequencies to 1,000Hz and 2,000Hz, respectively. Stimuli were delivered binaurally. Results Mean age of participants was 35 years. Average P300 latency was 305ms. Conclusion Maximum acceptable P300 latency values of 362.5ms (305 + 2SD 28.75) were determined for adults aged 18 to 59 years using the protocol described.

Teste melódico de processamento temporal: análise de diferentes formas de respostas

Purpose Evaluate the results of the different forms of responses in the melodic temporal ordering test in relation to frequency and duration. Methods The sample was composed of 33 subjects, for convenience, aged between 17 and 27 years old, normal hearing individuals, presenting no complaints regarding auditory processing and having no hearing impairment, syndromes or craniofacial malformation history; no physical disability (manual), as well as no neurological and speech impairment and education level greater than nine years. They were subjected to the temporal ordering test with musical tone, called melodic Duration Pattern Test (DPT) and Frequency Pattern Test (FPT), applied under three response conditions (motor, humming and motor), performed on the same date. For that, at a first moment, the induvial were asked to recognize the stimuli verbally, then characterize the stimuli in an imitative pattern and, finally, to recognize the stimuli in manual responses. Results Statistically significant differences were not observed between the three forms of responses for DPT and FPT. However, it is remarkable that there was a greater number of changes for FPT than for DPT, regardless the form of response. Furthermore, motor and verbal responses presented more changes for humming, in FPT. Conclusion The different forms of response (motor, humming and motor) for the melodic DPT and FPT did not change the results.