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Canine Audiology
Published in Stavros Hatzopoulos, Andrea Ciorba, Mark Krumm, Advances in Audiology and Hearing Science, 2020
Kristine E. Sonstrom, Peter M. Scheifele
The ABR test is an auditory electrophysiologic measure of synaptic activity within the auditory nerve and brainstem. This routine technique has been used with humans since 1967 (Hall, 2007) and slowly introduced into the animal industry since the 1980s (Kay et al., 1984; Myers et al., 1985; Sims and Moore, 1984a; Sims, 1988). It is an objective measure of electrical potentials produced by the brain in response to sound stimuli by the synchronous discharge of neurons in the auditory nerve and brainstem (Hall, 2007). The generated response is averaged by the computer and displayed as a waveform, typically with five to seven peaks, as shown in Figure 5.6.
Hearing Aids for the Pediatric Population
Published in Stavros Hatzopoulos, Andrea Ciorba, Mark Krumm, Advances in Audiology and Hearing Science, 2020
Katia de Almeida, Maria Cecíli Martinelli
Procedures such as ABR, OAE, and acoustic immittance measures assist in determining the mechanical and neural integrity of the auditory system. It is important to remember that the ABR is not a hearing test, instead, it measures neural synchrony, which results from the simultaneous firing of a large group of neurons in response to the sound (ASHA, 2004). Still, it the lowest levels of repeatable frequency-specific ABR thresholds can be used to estimate behavioral thresholds (if correction factors are used).
Chronic Hyperglycemia Impairs Vision, Hearing, and Sensory Function
Published in Robert Fried, Richard M. Carlton, Type 2 Diabetes, 2018
Robert Fried, Richard M. Carlton
Auditory evoked potentials are used to determine the integrity of hearing and to make inferences about how well it works. The ABR is an auditory evoked potential observed in ongoing electrical activity in the brain and recorded by means of electrodes placed on the scalp. The measured recording is a series of six to seven vertex positive waves, of which I through V are evaluated. These waves, labeled with Roman numerals (V is 5), occur in the first 10 ms after onset of an auditory stimulus. The ABR is considered an exogenous response because it depends on external factors (Hall. 2007; Eggermont, Burkard, and Manuel. 2007).
Auditory brainstem response in autistic children: implications for sensory processing
Published in Hearing, Balance and Communication, 2023
Garrett Cardon, Madelyn Cate, Sarah Cordingley, Brittany Bown
In addition to common uses of ABR, such as threshold estimation and hearing screening, ABRs have also been hypothesised in numerous studies as a possible diagnostic tool for autism. ABR testing is widely available and relatively low cost, which increases its desirability as a diagnostic or evaluation tool. Unfortunately, the results of studies of ABR in autism have varied. For instance, it seems the majority of such studies have indicated that autistic people have prolonged ABR waves I, III and V [20,24–27]. Additionally, autistic people have been shown to have notably reduced ABR waveform peak amplitudes [27,28]. In contrast, there are several studies that disagree with the above claims [29–32]. The reasons for these discrepancies across the literature are yet unknown. However, inconsistencies in ABR findings could be due to the heterogeneity of the autism population or methodological differences between studies.
Assessment of the cochlear implant pathway for newborn hearing screening referrals
Published in Cochlear Implants International, 2021
Rajeev Mathew, Fernando Rodriguez Bajo, Nicola Hatton, Louise Buttfield, Shravan Gowrishankar, Deborah Vickers, Neil Donnelly, James Tysome, Manohar Bance, Patrick Axon
The presence of OME was associated with a significant delay in CI surgery. All children underwent a period of observation after the diagnosis of OME, but natural resolution only occurred in 2/19 cases (10.5%) and 18/19 cases went on to have CI surgery anyway. As a result, we have removed the ‘watchful waiting’ period and children are immediately placed on the waiting list for ventilation tube surgery after diagnosis of OME. Surgery is performed within 4 weeks, with a second assessment including tympanometry prior to this. Ventilation tube surgery is not mandatory however, if the child had a local ABR confirming severe – profound hearing loss in the absence of OME or if behavioural audiometry confirms no measurable bone-conduction hearing. Previous studies have shown that CI in the presence of active OME is safe (Cevizci et al., 2018; Sokolov et al., 2016). It is our practice to avoid ABR testing in the same sitting as ventilation tube surgery. This is because ventilation tube surgery is associated with a temporary threshold shift in hearing (Griffiths et al., 2007) and thresholds may be overestimated by as much as 20 dB HL.
Intraoperative determination of coupling efficiency of Carina® middle ear implant by means of auditory evoked potentials
Published in International Journal of Audiology, 2020
Mario Cebulla, Rudolf Hagen, Kristen Rak, Ute Geiger
The intraoperative measurements were conducted in two steps. Immediately after the placement of the fixation unit for the actuator, the load of the actuator was adjusted by the surgeon according to the recommended positioning procedure which is based on the monitoring of the electrical impedance of the actuator using the manufacturer’s adjustment equipment. In the next step, the monitoring system was replaced by the ABR system. For the acoustical stimulation, an alternating stimulus with a stimulation rate of 49.1/s was used. The initial stimulation level was based on preoperatively measured BC thresholds plus about 15–20 dB and was varied, in 10-dB steps, down to the ABR threshold. In the threshold region, 5-dB steps were used. The evaluation of the ABR was done visually by an experienced audiologist. For every measurement, 2,000 single responses to alternating stimuli were collected. The artefact threshold was set to 40 µV. In general, at least three measurements were performed at different stimulation levels, resulting in, typically, in a total elapsed time of approximately 10 min for one session.