The Detection of Infant Cortical Auditory Evoked Potentials (CAEPs) Using Statistical and Visual Detection Techniques
The Detection of Infant Cortical Auditory Evoked Potentials (CAEPs) Using Statistical and Visual Detection Techniques
Abstract
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 (d9) and the area under the receiver operating characteristic (ROC) curve.
Results: Results showed that as the stimulus level increased, the sensitivity index, d9, increased for both
methods of response detection, but neither reached the maximum possible d9 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.
Cortical auditory evoked potentials
Infants
Normal hearing
Abstract
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 (d9) and the area under the receiver operating characteristic (ROC) curve.
Results: Results showed that as the stimulus level increased, the sensitivity index, d9, increased for both
methods of response detection, but neither reached the maximum possible d9 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.
Cortical auditory evoked potentials
Infants
Normal hearing