The detection of adult cortical auditory evoked potentials (CAEPs) using an automated statistic and visual detection

Abstract

The detection of adult cortical auditory evoked potentials (CAEPs) can be challenging when the stimulus is just audible. The effectiveness of a statistic compared with expert examiners in (1) detecting the presence of CAEPs when stimuli were present, and (2) reporting the absence of CAEPs when no stimuli were present, was investigated. CAEPs recorded from ten adults, using two speech-based stimuli, five stimulus presentation levels, and non-stimulus conditions, were given to four experienced examiners who were asked to determine if responses to auditory stimulation could be observed, and their degree of certainty in making their decision. These recordings were also converted to multiple dependent variables and Hotelling's T2 was applied to calculate the probability that the mean value of any linear combination of these variables was significantly different from zero. Results showed that Hotelling's T2 was equally sensitive to the best of individual experienced examiners in differentiating a CAEP from random noise. It is reasonable to assume that the difference in response detection for a novice examiner and Hotelling's T2 would be even greater.

Objective measures for detecting the auditory brainstem response: comparisons of specificity, sensitivity and detection time

“…Hence, although 25 TVMs may be a relatively 648 robust set of features for ABR detection, it is not necessarily optimal, and it may be beneficial to use 649 more specific arrangements of TVMs depending on the type of stimulus and/or stimulus parameters 650 being used. A general rule of thumb is that the optimal number of TVMs will tend to increase along 651 with the number of peaks in the ABR, since consecutive time-domain peaks within the ABR would 652 cancel each other out when the number of TVMs is too low (Golding, 2009). Hence, when the 653 stimulus intensity is decreased, and ABR waves I and III begin to disappear (Hall, 2006), it may be 654 beneficial to use fewer TVMs.…”

Induced activity in EEG in response to auditory stimulation

“…However, the adopted approach facilitates visualising the spectrogram of the evoked response and comparing it to that of the induced response. Given that the shape of evoked responses to tone bursts are documented in previous work [14,15,16], visualising its spectrogram can act as a quality check for methods used. Also, in the WS protocol, it was not clear from previous work if there was an induced response present, or in which frequency band the signal had to be filtered to observe an evoked response.…”

“…Furthermore, there is no study that may be particularly relevant to assessing hearing-impaired patient's access to speech. The brain's response to repeating pure tones has attracted much attention in audiology and has been shown to be beneficial for objective estimation of the hearing threshold [14,15,16]. For the purpose of finding hearing threshold, the brain response is typically analysed in the time domain focusing on the evoked response [14] to different sound levels of pure tones.…”

Cortical Auditory Evoked Potential: evaluation of speech detection in adult hearing aid users

“…It is also possible to observe great variability concerning range, latency, and morphology of inter-and intrasubject responses; there is also variance concerning the type and the characteristics of the stimulus. Therefore, by considering the significant maturational changes occurring in CAEP throughout development, the major variability of responses, besides the technical limitation of electrodes, filters, and amplifiers to capture these potentials, added to the difficulty to interpret responses and the high costs of the equipment, the clinical use of CAEP has been hampered until recently (3,4) . The increasing number of infants, who were diagnosed early by neonatal auditory screening programs, being referred to the adaptation of hearing aids created challenges related to speech language pathology and audiology.…”

“…For an adult, the P1 wave is characterized by a small positive peak, with latency of approximately 50 ms after stimulus; one high negative peak (N1), about 100 ms after the stimulus begins; and one second high positive peak (P2), about 200 ms after stimulus. The auditory assessment using the CAEPs presents several advantages, because it allows evaluating the whole auditory system (from the brain stem to the cortex) and because it can be registered among awake participants, obtained with a variety of acoustic stimuli presented both with headphones and in free field, which is an especially favorable situation (1,3) . Even if the clinical and scientific value of these potentials is inestimable, the daily use of these cortical potentials were compromised in the past, due to several factors.…”