The Relationship between Obligatory Cortical Auditory Evoked Potentials (CAEPs) and Functional Measures in Young Infants

Finding ways to evaluate the success of hearing aid fittings in young infants has increased in importance with the implementation of hearing screening programs. Cortical auditory evoked potentials (CAEP) can be recorded in infants and provides evidence for speech detection at the cortical level. The validity of this technique as a tool of hearing aid evaluation needs, however, to be demonstrated. The present study examined the relationship between the presence/absence of CAEPs to speech stimuli and the outcomes of a parental questionnaire in young infants who were fitted with hearing aids. The presence/absence of responses was determined by an experienced examiner as well as by a statistical measure, Hotelling's T2. A statistically significant correlation between CAEPs and questionnaire scores was found using the examiner's grading (rs = 0.45) and using the statistical grading (rs = 0.41), and there was reasonably good agreement between traditional response detection methods and the statistical analysis. La búsqueda de formas de evaluar el éxito de una adaptación de auxiliares auditivos en niños pequeños ha aumentado en importancia con la implementación de los programas de tamizaje auditivo. Se pueden registrar potenciales evocados auditivos corticales (CAEP) en infantes y aportar evidencia sobre la detección del lenguaje a nivel cortical. La validez de esta técnica como una herramienta para la evaluación de las necesidades de adaptación de auxiliares auditivos necesita, sin embargo, ser demostrada. El presente estudio examinó la relación entre la presencia/ausencia de CAEP ante estímulos de lenguaje y el resultado de un cuestionario a los padres de infantes a los que se adaptaron auxiliares auditivos. La presencia/ausencia de respuestas fue determinada por un examinador con experiencia, así como por un procedimiento de medición estadística: la T2 de Hotelling. Se encontró una correlación estadísticamente significativa entre los CAEP y los puntajes del cuestionario, utilizando la gradación del examinador (rs = 0.45) y utilizando la gradación estadística (rs = 0.41), y existió un acuerdo razonablemente bueno entre los métodos tradicionales de detección de respuesta y el análisis estadístico.

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Electroacoustic Comparison of Hearing Aid Output of Phonemes in Running Speech versus Isolation: Implications for Aided Cortical Auditory Evoked Potentials Testing

International Journal of Otolaryngology ◽

10.1155/2012/518202 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 6

Author(s):

Vijayalakshmi Easwar ◽

David W. Purcell ◽

Susan D. Scollie

Keyword(s):

Evoked Potentials ◽

Hearing Aids ◽

Auditory Evoked Potentials ◽

Hearing Aid ◽

Conversational Speech ◽

Individual Basis ◽

The Past ◽

Cortical Auditory Evoked Potentials

Background. Functioning of nonlinear hearing aids varies with characteristics of input stimuli. In the past decade, aided speech evoked cortical auditory evoked potentials (CAEPs) have been proposed for validation of hearing aid fittings. However, unlike in running speech, phonemes presented as stimuli during CAEP testing are preceded by silent intervals of over one second. Hence, the present study aimed to compare if hearing aids process phonemes similarly in running speech and in CAEP testing contexts.Method. A sample of ten hearing aids was used. Overall phoneme level and phoneme onset level of eight phonemes in both contexts were compared at three input levels representing conversational speech levels.Results. Differences of over 3 dB between the two contexts were noted in one-fourth of the observations measuring overall phoneme levels and in one-third of the observations measuring phoneme onset level. In a majority of these differences, output levels of phonemes were higher in the running speech context. These differences varied across hearing aids.Conclusion. Lower output levels in the isolation context may have implications for calibration and estimation of audibility based on CAEPs. The variability across hearing aids observed could make it challenging to predict differences on an individual basis.

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Cortical Auditory Evoked Potentials in the Assessment of Auditory Neuropathy: Two Case Studies

Journal of the American Academy of Audiology ◽

10.3766/jaaa.18.5.3 ◽

2007 ◽

Vol 18 (05) ◽

pp. 380-390 ◽

Cited By ~ 26

Author(s):

Wendy Pearce ◽

Maryanne Golding ◽

Harvey Dillon

Keyword(s):

Evoked Potentials ◽

Case Studies ◽

Auditory Evoked Potentials ◽

Auditory Neuropathy ◽

Auditory Brainstem Responses ◽

Cochlear Function ◽

Screening Programs ◽

Young Infants ◽

Brainstem Function ◽

Cortical Auditory Evoked Potentials

Infants with auditory neuropathy and possible hearing impairment are being identified at very young ages through the implementation of hearing screening programs. The diagnosis is commonly based on evidence of normal cochlear function but abnormal brainstem function. This lack of normal brainstem function is highly problematic when prescribing amplification in young infants because prescriptive formulae require the input of hearing thresholds that are normally estimated from auditory brainstem responses to tonal stimuli. Without this information, there is great uncertainty surrounding the final fitting. Cortical auditory evoked potentials may, however, still be evident and reliably recorded to speech stimuli presented at conversational levels. The case studies of two infants are presented that demonstrate how these higher order electrophysiological responses may be utilized in the audiological management of some infants with auditory neuropathy. Los niños con neuropatía auditiva y posibles posibles trastornos auditivos están siendo identificados a edades tempranas con la implementación de programas de tamizaje auditivo. El diagnóstico se basa en la evidencia de una función coclear normal pero de una función anormal del tallo cerebral. Esta falta de función normal de tallo cerebral es muy problemática cuando se trata de prescribir amplificación en niños pequeños, porque las fórmulas de prescripción requieren el insumo de los umbrales auditivos que se estiman normalmente a partir de las respuestas del tallo cerebral ante estímulos tonales. Sin esta información, existe una gran incertidumbre en cuanto a la adaptación final. Los potenciales evocados auditivos corticales pueden, sin embargo, registrarse con confiabilidad a partir de estímulos de lenguaje presentados a niveles de intensidad para la conversación. Se presenta el estudio de dos casos de niños, que demuestran como estas respuestas electrofisiológicas de orden mayor pueden utilizarse en el manejo audiológico de algunos niños con neuropatía auditiva.

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Cortical Auditory-Evoked Potentials (CAEPs) in Adults in Response to Filtered Speech Stimuli

Journal of the American Academy of Audiology ◽

10.3766/jaaa.24.9.5 ◽

2013 ◽

Vol 24 (09) ◽

pp. 807-822 ◽

Cited By ~ 11

Author(s):

Lyndal Carter ◽

Harvey Dillon ◽

John Seymour ◽

Mark Seeto ◽

Bram Van Dun

Keyword(s):

Hearing Loss ◽

Evoked Potentials ◽

Hearing Aids ◽

Auditory Evoked Potentials ◽

Hearing Aid ◽

Speech Sounds ◽

Sensation Level ◽

Behavioral Threshold ◽

Speech Stimuli ◽

Cortical Auditory Evoked Potentials

Background: Previous studies have demonstrated that cortical auditory-evoked potentials (CAEPs) can be reliably elicited in response to speech stimuli in listeners wearing hearing aids. It is unclear, however, how close to the aided behavioral threshold (i.e., at what behavioral sensation level) a sound must be before a cortical response can reliably be detected. Purpose: The purpose of this study was to systematically examine the relationship between CAEP detection and the audibility of speech sounds (as measured behaviorally), when the listener is wearing a hearing aid fitted to prescriptive targets. A secondary aim was to investigate whether CAEP detection is affected by varying the frequency emphasis of stimuli, so as to simulate variations to the prescribed gain-frequency response of a hearing aid. The results have direct implications for the evaluation of hearing aid fittings in nonresponsive adult clients, and indirect implications for the evaluation of hearing aid fittings in infants. Research Design: Participants wore hearing aids while listening to speech sounds presented in a sound field. Aided thresholds were measured, and cortical responses evoked, under a range of stimulus conditions. The presence or absence of CAEPs was determined by an automated statistic. Study Sample: Participants were adults (6 females and 4 males). Participants had sensorineural hearing loss ranging from mild to severe-profound in degree. Data Collection and Analysis: Participants' own hearing aids were replaced with a test hearing aid, with linear processing, during assessments. Pure-tone thresholds and hearing aid gain measurements were obtained, and a theoretical prediction of speech stimulus audibility for each participant (similar to those used for audibility predictions in infant hearing aid fittings) was calculated. Three speech stimuli, (/m/, /t/, and /g/) were presented aided (monaurally, nontest ear occluded), free field, under three conditions (+4 dB/octave, −4 dB/octave, and without filtering), at levels of 40, 50, and 60 dB SPL (measured for the unfiltered condition). Behavioral thresholds were obtained, and CAEP recordings were made using these stimuli. The interaction of hearing loss, presentation levels, and filtering conditions resulted in a range of CAEP test behavioral sensation levels (SLs), from −25 to +40 dB. Results: Statistically significant CAEPs (p < .05) were obtained for virtually every presentation where the behavioral sensation level was >10 dB, and for only 5% of occasions when the sensation level was negative. In these (“false-positive”) cases, the greatest (negative) sensation level at which a CAEP was judged to be present was −6 dB SL. Conclusions: CAEPs are a sensitive tool for directly evaluating the audibility of speech sounds, at least for adult listeners. CAEP evaluation was found to be more accurate than audibility predictions, based on threshold and hearing aid response measures.

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A Pilot Study on Cortical Auditory Evoked Potentials in Children: Aided CAEPs Reflect Improved High-Frequency Audibility with Frequency Compression Hearing Aid Technology

International Journal of Otolaryngology ◽

10.1155/2012/982894 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 18

Author(s):

Danielle Glista ◽

Vijayalakshmi Easwar ◽

David W. Purcell ◽

Susan Scollie

Keyword(s):

Evoked Potentials ◽

Hearing Aids ◽

Auditory Evoked Potentials ◽

Time Window ◽

Hearing Aid ◽

Older Children ◽

Frequency Compression ◽

Cortical Responses ◽

Cortical Auditory Evoked Potentials ◽

Hearing Aid Benefit

Background. This study investigated whether cortical auditory evoked potentials (CAEPs) could reliably be recorded and interpreted using clinical testing equipment, to assess the effects of hearing aid technology on the CAEP.Methods. Fifteen normal hearing (NH) and five hearing impaired (HI) children were included in the study. NH children were tested unaided; HI children were tested while wearing hearing aids. CAEPs were evoked with tone bursts presented at a suprathreshold level. Presence/absence of CAEPs was established based on agreement between two independent raters.Results. Present waveforms were interpreted for most NH listeners and all HI listeners, when stimuli were measured to be at an audible level. The younger NH children were found to have significantly different waveform morphology, compared to the older children, with grand averaged waveforms differing in the later part of the time window (the N2 response). Results suggest that in some children, frequency compression hearing aid processing improved audibility of specific frequencies, leading to increased rates of detectable cortical responses in HI children.Conclusions. These findings provide support for the use of CAEPs in measuring hearing aid benefit. Further research is needed to validate aided results across a larger group of HI participants and with speech-based stimuli.

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New possibility for measuring the cortical auditory evoked potentials: the HEARLab

Orvosi Hetilap ◽

10.1556/oh.2014.29992 ◽

2014 ◽

Vol 155 (38) ◽

pp. 1524-1529

Author(s):

Ádám Bach ◽

Ferenc Tóth ◽

Vera Matievics ◽

József Géza Kiss ◽

József Jóri ◽

...

Keyword(s):

Clinical Practice ◽

Evoked Potentials ◽

Auditory System ◽

Hearing Aids ◽

Pure Tone ◽

Auditory Evoked Potentials ◽

Normal Hearing ◽

Speech Stimuli ◽

Novel Method ◽

Cortical Auditory Evoked Potentials

Introduction: Cortical auditory evoked potentials can provide objective information about the highest level of the auditory system. Aim: The purpose of the authors was to introduce a new tool, the “HEARLab” which can be routinely used in clinical practice for the measurement of the cortical auditory evoked potentials. In addition, they wanted to establish standards of the analyzed parameters in subjects with normal hearing. Method: 25 adults with normal hearing were tested with speech stimuli, and frequency specific examinations were performed utilizing pure tone stimuli. Results: The findings regarding the latency and amplitude analyses of the evoked potentials confirm previously published results of this novel method. Conclusions: The HEARLAb can be a great help when performance of the conventional audiological examinations is complicated. The examination can be performed in uncooperative subjects even in the presence of hearing aids. The test is frequency specific and does not require anesthesia. Orv. Hetil., 2014, 155(38), 1524–1529.

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The Detection of Infant Cortical Auditory Evoked Potentials (CAEPs) Using Statistical and Visual Detection Techniques

Journal of the American Academy of Audiology ◽

10.3766/jaaa.21.5.6 ◽

2010 ◽

Vol 21 (05) ◽

pp. 347-356 ◽

Cited By ~ 36

Author(s):

Lyndal Carter ◽

Maryanne Golding ◽

Harvey Dillon ◽

John Seymour

Keyword(s):

Evoked Potentials ◽

Repeated Measures ◽

Auditory Evoked Potentials ◽

Sensitivity Index ◽

Screening Programs ◽

Hotelling's T2 ◽

Hotelling’S T2 ◽

Response Detection ◽

Cortical Auditory Evoked Potentials ◽

Experienced Examiner

Background: With the advent of newborn hearing screening programs, the need to verify the fit of hearing aids in young infants has increased. The recording of cortical auditory evoked potentials (CAEPs) for this purpose is quite feasible, but rapid developmental changes that affect response morphology and the presence of electrophysiological noise can make subjective response detection challenging. Purpose: The purpose of this study was to investigate the effectiveness of an automated statistic versus experienced examiners in detecting the presence of infant CAEPs when stimuli were present and reporting the absence of CAEPs when no stimuli were present. Research Design: A repeated-measures design was used where infant-generated CAEPs were interpreted by examiners and an automated statistic. Study Sample: There were nine male and five female infants (mean age, 12 mo; SD, 3.4) who completed behavioral and electrophysiological testing using speech-based stimuli. Data Collection and Analysis: In total, 87 infant CAEPs were recorded to three sensation levels, 10, 20 and 30 dB relative to the behavioral thresholds and to nonstimulus trials. Three examiners were presented with these responses: (1) “in series,” where waveforms were presented in order of decreasing stimulus presentation levels, and (2) “nonseries,” where waveforms were randomized completely and presented as independent waveforms. The examiners were given no information about the stimulus levels and were asked to determine whether responses to auditory stimulation could be observed and their degree of certainty in making their decision. Data from the CAEP responses were also converted to multiple dependent variables and analyzed using Hotelling's T2. Results from both methods of response detection were analyzed using a repeated measures ANOVA (analysis of variance) and parameters of signal detection theory known as d-prime (d′) and the area under the receiver operating characteristic (ROC) curve. Results: Results showed that as the stimulus level increased, the sensitivity index, d′, increased for both methods of response detection, but neither reached the maximum possible d′ value with a sensation level of 30 dB. The examiners with the greatest experience and Hotelling's T2 were equally sensitive in differentiating the CAEP from noise. Conclusions: Hotelling's T2 appears to detect CAEPs from normal hearing infants at a rate equal to that of an experienced examiner. A clinical instrument that applies Hotelling's T2 on-line, so that the likelihood of response detection can be assessed objectively, should be of particular benefit to the novice or less experienced examiner.

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