title: Influence of Acoustic Overstimulation on the Central Auditory System: An Functional Magnetic Resonance Imaging (fMRI) Study.
abstract: BACKGROUND The goal of the fMRI experiment was to explore the involvement of central auditory structures in pathomechanisms of a behaviorally manifested auditory temporary threshold shift in humans. MATERIAL AND METHODS The material included 18 healthy volunteers with normal hearing. Subjects in the exposure group were presented with 15 min of binaural acoustic overstimulation of narrowband noise (3 kHz central frequency) at 95 dB(A). The control group was not exposed to noise but instead relaxed in silence. Auditory fMRI was performed in 1 session before and 3 sessions after acoustic overstimulation and involved 3.5-4.5 kHz sweeps. RESULTS The outcomes of the study indicate a possible effect of acoustic overstimulation on central processing, with decreased brain responses to auditory stimulation up to 20 min after exposure to noise. The effect can be seen already in the primary auditory cortex. Decreased BOLD signal change can be due to increased excitation thresholds and/or increased spontaneous activity of auditory neurons throughout the auditory system. CONCLUSIONS The trial shows that fMRI can be a valuable tool in acoustic overstimulation studies but has to be used with caution and considered complimentary to audiological measures. Further methodological improvements are needed to distinguish the effects of TTS and neuronal habituation to repetitive stimulation.
authors.affiliation: Institute of Physiology and Pathology of Hearing, World Hearing Center, Warsaw/Kajetany, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Wolak
authors.affiliation: Institute of Physiology and Pathology of Hearing, World Hearing Center, Warsaw/Kajetany, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Cieśla
authors.affiliation: Institute of Physiology and Pathology of Hearing, World Hearing Center, Warsaw/Kajetany, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Rusiniak
authors.affiliation: Institute of Physiology and Pathology of Hearing, World Hearing Center, Warsaw/Kajetany, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Piłka
authors.affiliation: Institute of Physiology and Pathology of Hearing, World Hearing Center, Warsaw/Kajetany, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Lewandowska
authors.affiliation: Institute of Physiology and Pathology of Hearing, World Hearing Center, Warsaw/Kajetany, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Pluta
authors.affiliation: Institute of Physiology and Pathology of Hearing, World Hearing Center, Warsaw/Kajetany, Poland.
authors.forename: Henryk
authors.initials: H
authors.lastname: Skarżyński
authors.affiliation: Institute of Physiology and Pathology of Hearing, World Hearing Center, Warsaw/Kajetany, Poland.|Department of Heart Failure and Cardiac Rehabilitation, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Piotr H
authors.initials: PH
authors.lastname: Skarżyński
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D000328:Adult; D001303:Auditory Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D001305:Auditory Fatigue / Q000502:physiology*; D001309:Auditory Threshold / Q000502:physiology*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009622:Noise; D055815:Young Adult