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The influence of externalization and spatial cues on the generation of auditory brainstem responses and middle latency responses.
Hear Res. 2007 Mar; 225(1-2):91-104.HR

Abstract

The effect of externalization and spatial cues on the generation of auditory brainstem responses (ABRs) and middle latency responses (MLRs) was investigated in this study. Most previous evoked potential studies used click stimuli with variations of interaural time (ITDs) and interaural level differences (ILDs) which merely led to a lateralization of sound inside the subject's head. In contrast, in the present study potentials were elicited by a virtual acoustics stimulus paradigm with 'natural' spatial cues and compared to responses to a diotic, non-externalized reference stimulus. Spatial sound directions were situated on the horizontal plane (corresponding to variations in ITD, ILD, and spectral cues) or the midsagittal plane (variation of spectral cues only). An optimized chirp was used which had proven to be advantageous over the click since it compensates for basilar membrane dispersion. ABRs and MLRs were recorded from 32 scalp electrodes and both binaural potentials (B) and binaural difference potentials (BD, i.e., the difference between binaural and summed monaural responses) were investigated. The amplitudes of B and BD to spatial stimuli were not higher than those to the diotic reference. ABR amplitudes decreased and latencies increased with increasing laterality of the sound source. A rotating dipole source exhibited characteristic patterns in dependence on the stimulus laterality. For the MLR data, stimulus laterality was reflected in the latency of component N(a). In addition, dipole source analysis revealed a systematic magnitude increase for the dipole contralateral to the azimuthal position of the sound source. For the variation of elevation, the right dipole source showed a stronger activation for stimuli away from the horizontal plane. The results indicate that at the level of the brainstem and primary auditory cortex binaural interaction is mostly affected by interaural cues (ITD, ILD). Potentials evoked by stimuli with natural combinations of ITD, ILD, and spectral cues were not larger than those elicited by diotic chirps.

Authors+Show Affiliations

Medizinische Physik, Carl von Ossietzky Universität Oldenburg, D-26111 Oldenburg, Germany. d.junius@uni-oldenburg.deNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17270375

Citation

Junius, Dirk, et al. "The Influence of Externalization and Spatial Cues On the Generation of Auditory Brainstem Responses and Middle Latency Responses." Hearing Research, vol. 225, no. 1-2, 2007, pp. 91-104.
Junius D, Riedel H, Kollmeier B. The influence of externalization and spatial cues on the generation of auditory brainstem responses and middle latency responses. Hear Res. 2007;225(1-2):91-104.
Junius, D., Riedel, H., & Kollmeier, B. (2007). The influence of externalization and spatial cues on the generation of auditory brainstem responses and middle latency responses. Hearing Research, 225(1-2), 91-104.
Junius D, Riedel H, Kollmeier B. The Influence of Externalization and Spatial Cues On the Generation of Auditory Brainstem Responses and Middle Latency Responses. Hear Res. 2007;225(1-2):91-104. PubMed PMID: 17270375.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The influence of externalization and spatial cues on the generation of auditory brainstem responses and middle latency responses. AU - Junius,Dirk, AU - Riedel,Helmut, AU - Kollmeier,Birger, Y1 - 2006/12/19/ PY - 2005/06/08/received PY - 2006/12/10/revised PY - 2006/12/12/accepted PY - 2007/2/3/pubmed PY - 2007/5/17/medline PY - 2007/2/3/entrez SP - 91 EP - 104 JF - Hearing research JO - Hear Res VL - 225 IS - 1-2 N2 - The effect of externalization and spatial cues on the generation of auditory brainstem responses (ABRs) and middle latency responses (MLRs) was investigated in this study. Most previous evoked potential studies used click stimuli with variations of interaural time (ITDs) and interaural level differences (ILDs) which merely led to a lateralization of sound inside the subject's head. In contrast, in the present study potentials were elicited by a virtual acoustics stimulus paradigm with 'natural' spatial cues and compared to responses to a diotic, non-externalized reference stimulus. Spatial sound directions were situated on the horizontal plane (corresponding to variations in ITD, ILD, and spectral cues) or the midsagittal plane (variation of spectral cues only). An optimized chirp was used which had proven to be advantageous over the click since it compensates for basilar membrane dispersion. ABRs and MLRs were recorded from 32 scalp electrodes and both binaural potentials (B) and binaural difference potentials (BD, i.e., the difference between binaural and summed monaural responses) were investigated. The amplitudes of B and BD to spatial stimuli were not higher than those to the diotic reference. ABR amplitudes decreased and latencies increased with increasing laterality of the sound source. A rotating dipole source exhibited characteristic patterns in dependence on the stimulus laterality. For the MLR data, stimulus laterality was reflected in the latency of component N(a). In addition, dipole source analysis revealed a systematic magnitude increase for the dipole contralateral to the azimuthal position of the sound source. For the variation of elevation, the right dipole source showed a stronger activation for stimuli away from the horizontal plane. The results indicate that at the level of the brainstem and primary auditory cortex binaural interaction is mostly affected by interaural cues (ITD, ILD). Potentials evoked by stimuli with natural combinations of ITD, ILD, and spectral cues were not larger than those elicited by diotic chirps. SN - 0378-5955 UR - https://www.unboundmedicine.com/medline/citation/17270375/The_influence_of_externalization_and_spatial_cues_on_the_generation_of_auditory_brainstem_responses_and_middle_latency_responses_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0378-5955(06)00342-X DB - PRIME DP - Unbound Medicine ER -