Impact of Spectral Notch Width on Neurophysiological Plasticity and Clinical Effectiveness of the Tailor-Made Notched Music Training

PLoS One. 2015 Sep 25;10(9):e0138595. doi: 10.1371/journal.pone.0138595. eCollection 2015.

Abstract

Tinnitus, the ringing in the ears that is unrelated to any external source, causes a significant loss in quality of life, involving sleep disturbance and depression for 1 to 3% of the general population. While in the first place tinnitus may be triggered by damage to the inner ear cells, the neural generators of subjective tinnitus are located in central regions of the nervous system. A loss of lateral inhibition, tonotopical reorganization and a gain-increase in response to the sensory deprivation result in hypersensitivity and hyperactivity in certain regions of the auditory cortex. In the tailor-made notched music training (TMNMT) patients listen to music from which the frequency spectrum of the tinnitus has been removed. This evokes strong lateral inhibition from neurons tuned to adjacent frequencies onto the neurons involved in the tinnitus percept. A reduction of tinnitus loudness and tinnitus-related neural activity was achieved with TMNMT in previous studies. As the effect of lateral inhibition depends on the bandwidth of the notch, in the current study we altered the notch width to find the most effective notch width for TMNMT. We compared 1-octave notch width with ½-octave and ¼-octave. Participants chose their favorite music for the training that included three month of two hours daily listening. The outcome was measured by means of standardized questionnaires and magnetoencephalography. We found a general reduction of tinnitus distress in all administered tinnitus questionnaires after the training. Additionally, tinnitus-related neural activity was reduced after the training. Nevertheless, notch width did not have an influence on the behavioral or neural effects of TMNMT. This could be due to a non-linear resolution of lateral inhibition in high frequencies.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation / methods
  • Adult
  • Auditory Perception / physiology
  • Double-Blind Method
  • Evoked Potentials, Auditory*
  • Female
  • Humans
  • Magnetoencephalography
  • Male
  • Middle Aged
  • Music Therapy / methods*
  • Neuronal Plasticity*
  • Random Allocation
  • Surveys and Questionnaires
  • Tinnitus / physiopathology
  • Tinnitus / therapy*
  • Treatment Outcome

Grant support

This research was funded by "Interdisziplinäres Zentrum für klinische Forschung" IZKF (CRA05). Website: http://campus.uni-muenster.de/izkf.html. The funding was recieved by CR and CP. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.