The Physiological Basis and Clinical Use of the Binaural Interaction Component of the Auditory Brainstem Response

Abstract

The auditory brainstem response (ABR) is a sound-evoked non-invasively measured electrical potential representing the sum of neuronal activity in the auditory brainstem and midbrain. ABR peak amplitudes and latencies are widely used in human and animal auditory research and for clinical screening. The binaural interaction component (BIC) of the ABR stands for the difference between the sum of the monaural ABRs and the ABR obtained with binaural stimulation. The BIC comprises a series of distinct waves, the largest of which (DN1) has been used for evaluating binaural hearing in both normal hearing and hearing-impaired listeners. Based on data from animal and human studies, we discuss the possible anatomical and physiological bases of the BIC (DN1 in particular). The effects of electrode placement and stimulus characteristics on the binaurally evoked ABR are evaluated. We review how inter-aural time and intensity differences affect the BIC and, analyzing these dependencies, draw conclusion about the mechanism underlying the generation of the BIC. Finally, the utility of the BIC for clinical diagnoses are summarized.

Evidence for the origin of the binaural interaction component of the auditory brainstem response

“…It is based on two considerations: firstly, the amplitude and latency of the BIC ABR change characteristically with the ITD and, to a lesser extend, with the ILD of the stimulus. Observed consistently across species, irrespective of the relative sizes of their LSO and MSO (Irving & Harrison, ) or their head size (Benichoux et al., ; Laumen, Ferber et al., ), the BIC ABR amplitude decreases with increasing ITD or ILD and the latency of the BIC ABR increases with increasing ITD (guinea pig: Dobie & Berlin, ; human: Furst et al., ; cat: Ungan et al., ; guinea pig: Goksoy et al., ; human: Riedel & Kollmeier, ; gerbil: Laumen, Tollin et al., ; barn owl: Palanca‐Castan et al., ; rodent species: Benichoux et al., ). And secondly, any such dependence observed in a measure derived from a far‐field potential such as the ABR must have its source in the activity of single neurons and should be observable in the responses of those.…”

“…The search for the origin of the BIC ABR reaches almost as far back as its discovery (reviewed in Laumen, Ferber et al., ). More and more evidence has accumulated that the LSO in the auditory brainstem might be its source (computational model: Gaumond & Psaltikidou, ; cat: Ungan et al., ; guinea pig: Goksoy et al., ; human: Riedel & Kollmeier, ; rodent species: Benichoux et al., ).…”

“…ABRs are characterized by distinct positive and negative deflections that represent the activity of different stages along the auditory pathway (reviewed in Moller, ). The so‐called binaural interaction component (BIC) is associated with deflections in the ABR that represent the activity of stages of the auditory pathway that process binaural information (reviewed in Laumen, Ferber, et al., ). The BIC is revealed if the sum of responses to monaural left stimulation and monaural right stimulation is subtracted from the response to binaural stimulation (Dobie & Berlin, ).…”

“…The actual generators of the BIC are still being discussed (Laumen, Ferber et al., ; Palanca‐Castan, Laumen, Reed, & Köppl, ). Various findings point towards a source in the superior olivary complex (SOC), particularly the lateral and medial superior olives (LSO and MSO, respectively).…”

Responding to sounds from unseen locations: crossmodal attentional orienting in response to sounds presented from the rear

“…That said, it is also worth bearing in mind that the amplitude of the binaural interaction component (BIC) of the auditory brainstem response (ABR) relates directly to the perceived location of sounds (see Laumen et al ., , for a review). Furthermore, given that ILD and ITD are calculated in nuclei in the brainstem (MSO and LSO; see Celesia, ), and given the fact that the IC contains a map of auditory space, it would seem reasonable to suggest that the rapid orienting to sounds is mainly driven by brainstem activity.…”