Auditory Brainstem Encoding of Plosives in Korean Normal Hearing Listeners

이지현,한우재 한국청각언어재활학회 2017 Audiology and Speech Research Vol.13 No.2

Purpose: It is increasingly acknowledged that auditory brainstem response (ABR) elicited by speech can reflect the listener’s perceptual cues of complex sound with replicability and reliability. This study sought to identify the brainstem responses evoked by Korean syllables and to characterize any relation between acoustic features of the speech and their neurophysiological responses at the brainstem level. Methods: Thirty young adults with normal hearing who were native Korean speakers participated in the study. As speech stimuli, nine Korean syllables, i.e., a combination of nine plosives /p, p*, ph, t, t*, th, k, k*, kh/ followed by an /a/ vowel naturally produced by a male speaker, were applied for electrophysiological measure. Each waveform of the syllable was analyzed by seven peaks, V, A, C, D, E, F, and O, to determine latency, amplitude, and morphology. Results: According to transient responses, the peak V-A latencies of alveolar syllables were significantly delayed, while supporting their long voice onset time. Latencies of peak C for /ta/ and /t*a/ syllables were prolonged, having longer consonant duration. Although the latencies of peak O usually looked prolonged for the aspirate syllables, they did not support acoustic characteristics in terms of the end of voicing. In the view of sustained responses, a significant difference exists in latency for the D-E and E-F inter-peaks. However, unlike the transient response, no relation between sustain features and brainstem response was found. Conclusion: Speech-evoked ABR reflects clear and synchronized patterns of the brainstem, while providing information on the transient response regarding auditory pathway encoding of the plosive consonant portion of speech. It can provide a fundamental and biological snapshot of auditory processing that predicts auditory-based communication skills and gain.

청각신경병증 3예

김리석,정성욱,이승환,허승덕 대한이비인후과학회 2003 대한이비인후과학회지 두경부외과학 Vol.46 No.10

Auditory neuropathy is a hearing disorder characterized by an absent or severely abnormal auditory brainstem response, with preservation of the cochlear microphonics and otoacoustic emisions. This sugests that outer hair cell (OHC) function is normal tones and impaired word discrimination out of proportion to pure tone loss. Hearing aid alone is of little or no benefit in patients with auditory neuropathy. Visual support via cued spech or signed language can be a fail-safe method for insuring language de-velopment. Recently, there are some reports that cochlear implantation is highly sucesful in patients with auditory neuropathy. We report three cases (two children and one woman) with auditory neuropathy. Each patient was tested with cochlear microph-ear microphonics or otoacoustic emisions with absent auditory brainstem response. Two of them had evidence of a peripheral neuropathy. We should be aware of auditory neuropathy and implications for its management, which differs from treatment of sensorineural hearing loss. Auditory neuropathy also raises a concern about the risk of false-negative findings when newborn hearing screening is restricted to otoacoustic emissions. (Korean J Otolaryngol 2003 ;46 :874-881)

청성뇌간반응과 청성지속반응을 이용한 영유아의 청력역치 예측

김리석,정성욱 대한이비인후과학회 2011 대한이비인후과학회지 두경부외과학 Vol.54 No.9

Between one and three of every 1,000 neonates have sensorineural hearing loss (SNHL). It is of utmost importance to minimize the duration of auditory deprivation between the onset of bilateral deafness and intervention using hearing devices such as hearing aids and cochlear implants for achieving the best speech percpetion ability. To fit amplification accurately for children with SNHL, hearing thresholds for frequencies in the range of human communication should be evaluated. However, infants and young children are difficult to test using conventional behavioral tests, and hearing thresholds of them can be predicted using auditory brainstem response (ABR) and auditory steady-state response (ASSR). ABR is best evoked by applying a click stimulus, which allows an estimate over a broad range of high frequencies. ABR elicited by tone burst stimulus provides frequency-specific audiometric information. However, it can be difficult to record and observe at near-threshold levels, especially at lower frequencies. ABR thresholds for click and tone burst stimuli are highly correlated with behavioral thresholds, and often give an idea of the shape of an audiogram. ASSR is an auditory evoked potential, elicited with modulated tones. It provides frequency-specific hearing thresholds across the audiometric frequencies, which are well correlated with behavioral thresholds. However, the accuracy of threshold prediction decreases directly with the decrease of degree of hearing loss, and hearing thresholds cannot be predicted for auditory neuropathy. ASSR is most useful for estimating auditory thresholds for patients with no evidence of auditory neuropathy by the click ABR and OAEs, and who have an ABR only at high intensities or no ABR at a maximum stimulus level. Even if hearing thresholds are predicted through ABR and ASSR, behavioral testing including behavioral observation audiometry, visual reinforcement audiometry, or play audiometry should be employed repeatedly to verify the predicted thresholds, becasue the thresholds of ABR and ASSR are not true measure of hearing acuity but just responses generated at the brainstem.

국소적 뇌병소에 대한 뇌간청각 유발 전위 반응

강준기,조병일,백민우,김달수,허춘웅,하영수,송진언 대한신경외과학회 1983 Journal of Korean neurosurgical society Vol.12 No.1

Brainstem auditory response abnormalities directly reflect disturbance of neural function rather than the underlying anatomic cause of that disturbance. The test has advantages in detecting lesions that alter electrophysiology but do not produce detectable alterations of radiodensity, displace surrounding structures or change vascular supply and permeability. A sequence of seven low-amplitude potentials that occur in the initial 10 msec following click signals can be recorded from scalp electrodes in 44 patient with focal brain lesions using computer averaging techniques. The potentials, termed auditory brainstem responses, are thought to be the far - field reflection of electrical events originating in the auditory pathway during its course through the brainstem. We have studied auditory brainstem evoked potential responses in a variety of focal brain lesions and found them to be of assistance in evaluating the localization of pontomedullary, pons, midbrain, thalamus, subcortical and functional recovery. 1) Distortion of early components (type I) was occured in the brainstem lesions. 2) Distortion of late components (type II) was developed in the diencephalon or subcortical lesions. 3) Distortion of all components (type III) was developed in the brainstem and diffuse brain contusions. 4) Serial recordings provided information about the evolution of brain stem lesions and good functional recovery marker.

Auditory Brainstem Encoding of Plosives in Korean Normal Hearing Listeners

Jihyeon Lee,Woojae Han 한국청각언어재활학회 2017 Audiology and Speech Research Vol.13 No.2

Purpose: It is increasingly acknowledged that auditory brainstem response (ABR) elicited by speech can reflect the listener’s perceptual cues of complex sound with replicability and reliability. This study sought to identify the brainstem responses evoked by Korean syllables and to characterize any relation between acoustic features of the speech and their neurophysiological responses at the brainstem level. Methods: Thirty young adults with normal hearing who were native Korean speakers participated in the study. As speech stimuli, nine Korean syllables, i.e., a combination of nine plosives /p, p*, ph, t, t*, th, k, k*, kh/ followed by an /a/ vowel naturally produced by a male speaker, were applied for electrophysiological measure. Each waveform of the syllable was analyzed by seven peaks, V, A, C, D, E, F, and O, to determine latency, amplitude, and morphology. Results: According to transient responses, the peak V-A latencies of alveolar syllables were significantly delayed, while supporting their long voice onset time. Latencies of peak C for /ta/ and /t*a/ syllables were prolonged, having longer consonant duration. Although the latencies of peak O usually looked prolonged for the aspirate syllables, they did not support acoustic characteristics in terms of the end of voicing. In the view of sustained responses, a significant difference exists in latency for the D-E and E-F inter-peaks. However, unlike the transient response, no relation between sustain features and brainstem response was found. Conclusion: Speech-evoked ABR reflects clear and synchronized patterns of the brainstem, while providing information on the transient response regarding auditory pathway encoding of the plosive consonant portion of speech. It can provide a fundamental and biological snapshot of auditory processing that predicts auditory-based communication skills and gain.

Effect of Music Training on Auditory Brainstem and Middle Latency Responses

Chul-Hee Choi,Hea-Sung Cho 한국청각언어재활학회 2020 Audiology and Speech Research Vol.16 No.1

Purpose: The auditory system has potentials to reorganize its structure and function in response to environmental changes such as training, experience, learning, injury, and disease. This is called neuroplasticity. A typical example of neuroplasticity is the music training, which demands cognitive and neural challenges resulting in enhanced auditory perception. This study investigated the effect of music training on auditory evoked responses, particularly auditory brainstem and middle latency responses. Methods: Forty college students consisting of twenty students with music training (musicians) and twenty students without music training (non-musicians) participated in the study. All participants have normal ranges in terms of pure tone audiometry, speech audiometry, and tympanometry. Auditory brainstem response (ABR) and auditory middle latency response (AMLR) from both ears were tested. Absolute latencies and amplitudes of waves in ABR and AMLR were obtained and analyzed. Results: The absolute latencies of wave I and V significantly differed between musicians and non-musicians. They were shorter for musicians than for non-musicians. Significant differences were found in the interpeak latencies of wave III-V and I-V between musicians and non-musicians. They were also shorter in musicians than for non-musicians. In addition, there were only significant differences in the latency of Na in AMLR between musicians and non-musicians. It was shorter for a musician than for non-musician. Conclusion: ABR was more sensitive to the efficacy of the music training.

Brainstem Correlates of Comodulation Masking Release for Speech in Normal Hearing Adults

Soheila Rostami,Abdollah Moossavi,Mohsen Ahadi,Shohreh Jalaei 대한청각학회 2018 Journal of Audiology & Otology Vol.22 No.3

Weak signals embedded in fluctuating masker can be perceivedmore efficiently than similar signals embedded in unmodulated masker. This releasefrom masking is known as comodulation masking release (CMR). In this paper, we investigate,neural correlates of CMR in the human auditory brainstem. Subjects and Methods: Atotal of 26 normal hearing subjects aged 18-30 years participated in this study. First, theimpact of CMR was quantified by a behavioral experiment. After that, the brainstem correlatesof CMR was investigated by the auditory brainstem response to complex sounds (cABR) incomodulated (CM) and unmodulated (UM) masking conditions. Results: The auditory brainstemresponses are less susceptible to degradation in response to the speech syllable /da/ inthe CM noise masker in comparison with the UM noise masker. In the CM noise masker, frequency-following response (FFR) and fundamental frequency (F0) were correlated with betterbehavioral CMR. Furthermore, the subcortical response timing of subjects with higher CMRwas less affected by the CM noise masker, having higher stimulus-to-noise response correlationsover the FFR range. Conclusions: The results of the present study revealed a significantlink between brainstem auditory processes and CMR. The findings of the present studyshow that cABR provides objective information about the neural correlates of CMR forspeech stimulus.

Electrophysiological changes in auditory evoked potentials in rats with salicylate-induced tinnitus

Castañ,eda, Rodrigo,Natarajan, Sathishkumar,Jeong, Seo Yule,Hong, Bin Na,Kang, Tong Ho Elsevier/North Holland 2019 Brain research Vol.1715 No.-

<P><B>Abstract</B></P> <P>Early-response auditory evoked potentials (AEPs) in humans are significantly altered in tinnitus. These changes are closely related to that seen in animals, leading to new approaches to study tinnitus based on objective parameters. The purpose of this study was to characterize the AEPs in animals with tinnitus, by assessing early to late latency responses. For behavioral evaluation, rats were trained using positive reinforcement to press a lever in the presence of an auditory stimulus and to not press during silence. The auditory brainstem response (ABR), middle latency response (MLR) and auditory late latency response (LLR) were correlated to the false-positive responses (pressing the lever during silence), after oral administrations of Sodium Salicylate (SS, 350 mg/kg). In the present study, SS significantly increased the hearing thresholds and reduced ABR peak I amplitudes across the frequency range (4–32 kHz). In contrast, increased amplitudes were observed for several peaks in ABR, MLR, and LLR. Moreover, reduced ABR latencies in response to 8, 16 and 24 kHz tone bursts were observed after SS administration. Similarly, the central evaluation also revealed significantly reduced latencies in MLR and LLR during SS administration. In contrast, increased latencies were observed for ABR latencies in response to 32 kHz tone bursts, and at the P1-N1 component of LLR. Correlational analysis revealed that latencies and amplitudes of peaks II and IV (8 and 16 kHz) of ABR, and N2 latency and P2-N2 amplitude of LLR were associated with behavioral tinnitus. We suggest that AEPs can be used in the rat to evaluate the reduced sensory input and the increased central gain in SS-induced tinnitus, as well as reduced latencies (8–16 kHz) to distinguish between hearing loss and tinnitus.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Objective parameters of the AEPs were identified in rats treated with SS. </LI> <LI> Reduced sensory input was shown by hearing thresholds and ABR peak I amplitudes. </LI> <LI> Reduced latencies were found in the ABR (8-24kHz), MLR and LLR in SS-induced tinnitus. </LI> <LI> Central gain was reflected by increased amplitudes in ABR, MLR, and LLR. </LI> <LI> Behavioral tinnitus was correlated to peak IV of ABR, and P2 and N2 of LLR. </LI> </UL> </P>

Effects of Residual Hearing on the Auditory Steady State Response for Cochlear Implantation in Children

김영석,한선아,우현준,서명환,이준호,오승하,박무균 대한청각학회 2019 Journal of Audiology & Otology Vol.23 No.3

Background and Objectives: We aim to explore the effects of residual auditory steady state response (ASSR) on cochlear implantation (CI) outcomes in children lacking auditory brainstem responses (ABRs). Subjects and Methods: We retrospectively reviewed the data of child CI recipients lacking ABRs. All ears were divided into two groups: with residual ASSR and without ASSR. For each frequency, the T- and C-levels and the electrical dynamic ranges of postoperative 3-month and 1-year mappings were compared between the groups. To evaluate speech perception, patients who received simultaneous bilateral CIs were divided into two groups: group 1 exhibited responses at all frequencies in both ears; in group 2, at least one ear evidenced no response. The Categories of Auditory Perception (CAP) and Infant- Toddler Meaningful Auditory Integration Scale (IT-MAIS) scores were compared between the groups. Results: We enrolled 16 patients. At 2 kHz, the postoperative 3-month and 1-year T-levels of patients with residual hearing were lower than those of hearing loss group (p=0.001, p=0.035). In residual hearing group, the ASSR threshold correlated positively with the postoperative 1-year T-level (p=0.012, R2=0.276) and C-level (p=0.002, R2=0.374). Of 10 simultaneous bilateral CI recipients, 5 exhibited ASSRs at all frequencies and the other 5 showed no response at ≥1 frequency. The latter had higher CAP scores at the postoperative 1-year (p=0.018). Conclusions: In children exhibiting hearing loss in ABR testing, residual hearing at 2 kHz ASSR correlated positively with the post-CI T-level. Those with ASSRs at all frequencies had significantly lower CAP scores at the postoperative 1year. CI should not be delayed when marginal residual hearing is evident in ASSR.

Tone Burst 자극음을 이용한 골전도 청성뇌간유발반응(ABR)의 임상적 유용성 연구

김지현(Jihyun Kim),김진숙(Jinsook Kim) 한국언어청각임상학회 2002 Communication Sciences and Disorders Vol.7 No.3

골전도 청성뇌간유발반응검사(Auditory Brainstem Response: ABR)는 유소아의 와우 발달 상태와 청력의 형태를 추정할 수 있으며, 전음성 난청자와 외이도 폐쇄증이 있는 환자에게 사용할 수 있다고 알려져 있다. 이에 본 연구에서는 정상 청력을 지닌 20대의 성인을 대상으로 골전도 ABR과 주파수 정보를 얻을 수 있는 Tone Burst(TB)를 이용하여 임상에서 골전도의 유용성을 알아보려 하였다. 공기전도와 골전도에 사용된 자극음은 Click, TB500, TB2000을 사용하였다. 연구결과, 역치는 공기전도가 골전도보다 낮게 나타났으나, TB2000에서만 골전도 역치가 더 낮았다. 잠복기는 Click과 TB2000에서만 공기전도가 더 길었으며 골전도에서는 TB500에서만 잠복기가 더 길게 나타났고, 또한 모든 검사 반응의 진폭에서는 골전도가 더 크게 나타났다. 골전도에서도 자극 강도가 감소함에 따라 잠복기는 증가하는 형태를 보여 Intensity-Latency Function을 보였고 진폭은 감소하는 형태를 나타냈다. 골전도의 잠복기는 TB500, TB2000, Click의 순이었으며, 잠복기는 모두 서로 유의미하게 다른 것(p Auditory Brainstem Responses(ABRs) were recorded with Click, Tone Burst(TB) 500 Hz, 2000 Hz air conduction(AC) and bone conduction(BC) stimuli from normal hearing adults. With a Click at 20 dBHL, TB2000 responses were 100% detectable, but TB500 was 95% detectable. At 10 dBHL, Click and TB500 were detectable in 70% and 50% of the subjects and TB2000 was detectable in 90%. Latencies in Tone Bursts were significantly longer for BC compaired to AC. Wave V amplitude in BC was always larger than AC. Latency and Amplitude of the response were related to the stimuli. Both ipsilateral and contralateral responses were similar in latency, amplitude and morphology. Responses to Click, TB500 and TB2000 were different and the differences were statistically meaningful. Latencies to Click, TB500 and TB2000 were statistically different. However, amplitudes showed no significant difference except for the responses from ipsilateral 30 and 40 dB. When comparing air and bone conduction, only 50 dB Click and TB2000 showed a significant difference. Calculated slop b from TB500 was steeper than that of the other stimuli, whereas the slope of TB 2000 and Click were more flat. Moreover, TB500 showed the biggest intercept a. Derived-band analysis indicated a reasonably good frequency specificity for both the Tone Burst response and the bone-conducted Click response, despite it’s low frequency spectrum. The results of this study support the use of BC Tone Burst ABR for demonstrating normal frequency-specific cochlear sensitivity.