Frequency Characteristics of AEPs in Normal Young Adults and Comparison of Their Response Threshold and Pure Tone Audiometry Threshold / 法医学杂志

Objective The tests of three types of auditory evoked potentials （AEPs） were performed on normal young adults, to understand the frequency characteristics of different testing methods and the relationship between response threshold and pure tone audiometry threshold of different methods, and to discuss the forensic value of 3 types of AEPs to evaluate hearing function. Methods Twenty normal young adults were selected, their standard pure tone audiometry threshold, short-term pure tone audiometry threshold and the response threshold of 3 types of AEPs （tone burst-auditory brainstem response, 40 Hz auditory event-related potential and slow vertex response） at 0.5 kHz, 1.0 kHz, 2.0 kHz and 4.0 kHz were recorded. The relationship between the response threshold and standard pure tone audiometry threshold, short-term pure tone audiometry threshold of 3 types of AEPs at different frequencies as well as the differences between different types of AEPs were analyzed. Results The short-term pure tone audiometry threshold was higher than the standard pure tone audiometry threshold at each frequency. The response threshold and standard pure tone audiometry threshold of the 3 types of AEPs all had a certain correlation, and the response threshold of the 3 types of AEPs was higher than short-term pure tone audiometry threshold and standard pure tone audiometry threshold at each frequency. The differences in the differences between the response threshold and standard pure tone audiometry threshold of the 3 types of AEPs at different frequencies had statistical significance. Linear regression mathematical models were established to infer the standard pure tone audiometry threshold （hearing level） from response threshold （sound pressure level） of 3 types of AEPs of normal young adults. Conclusion When using response threshold of different types of AEPs to estimate pure tone audiometry threshold, conversion and correction are needed. Combined use of different types of AEPs could improve the accuracy of hearing function evaluation.

A Comparison of SVR and tb-ABR Response Threshold and PTA Threshold in Normal -hearing Young People / 听力学及言语疾病杂志

Objective To study the relationship among the slow vertex response (SVR) ,tone burst ABR threshold and pure tone thresholds in young people with normal hearing ,and to discuss the values of SVR and tb -ABR assessing hearing thresholds .Methods A total of 30 normal-hearing young people aged 20 to 24 were indud-ed in this study .The thresholds of SVR ,tb -ABR and threshold of PTA were tested at each verbal frequency (0 .5 ,1 ,2 ,4 kHz) .The differences and the relationship among SVR with PTA ,tb-ABR ,and PTA were statistical-ly studied .Results The differences between SVR and tb -ABR and PTA at various frequencies were statistically significant (P<0 .05) .The minimum difference between SVR and PTA was (3 .59 ± 7 .32) dB at 0 .5 kHz .The differences of 1 ,2 ,and 4 kHz were 6 .92 ± 5 .07 ,8 .33 ± 6 .71 ,and 9 .83 ± 9 .41 dB ,respectively .The minimum differences between tb -ABR and PTA was 14 .58 ± 7 .24 dB at 4 kHz ,and the differences of 0 .5 ,1 ,and 2 kHz were 29 .42 ± 6 .83 ,23 .25 ± 7 .47 ,and 16 .50 ± 6 .43 dB ,respectively .SVR and PTA had a good correlation at 1 and 2 kHz (r=0 .51 ,P<0 .01 and r=0 .44 ,P<0 .05 ,respectively) .tb-ABR and PTA had a good correlation at 4 kHz (r=0 .53 ,P<0 .01) .Conclusion In normal hearing young population ,SVR and tb-ABR can estimate PTA well , and the former is closer to PTA threshold .

Sensory, cognitive and motor assessment of children with poor academic performance: An auditory evoked potential study.

The present study aims to evaluate the auditory sensory process in the brainstem, thalamocortical and cortical areas by using auditory evoked potentials [auditory brainstem response (ABR), mid latency response (MLR) and slow vertex response (SVR)], cognitive functions by P300 and motor response by reaction time in children with poor academic performance. Thirty children between 6–12 years of age were selected as subjects on the basis of poor academic school records. While thirty children with good academic performance served as controls. The recordings were done using a computerized evoked potential recorder by 10–20 electrode placement system. There was no difference in the anthropometric parameters and IQ of the two groups. There was a significant increase in latency of waves II, III, IV and V, and Inter-peak latency I-V of ABR in poor performer females. All the component waves of MLR and SVR showed increased latency in the subjects but could not reach the level of significance. There was a significant increase in latencies of P300 at Cz and Pz electrode positions with no change in amplitude in poor performer females. The reaction time was also increased in the poor performer females as compared to the controls. The latencies of all the waves of ABR, P300 and reaction time are also increased in male poor performers as compared to male controls but could not reach the level of significance. The conduction of impulses is slower in pontine and midbrain auditory pathway along with inefficient cortical processing of task relevant stimuli and motor response in female children having poor academic performance.