No Need for Templates in the Auditory Enhancement Effect

PLoS One. 2013 Jun 27;8(6):e67874. doi: 10.1371/journal.pone.0067874. Print 2013.

Abstract

The audibility of a target tone in a multitone background masker is enhanced by the presentation of a precursor sound consisting of the masker alone. There is evidence that precursor-induced neural adaptation plays a role in this perceptual enhancement. However, the precursor may also be strategically used by listeners as a spectral template of the following masker to better segregate it from the target. In the present study, we tested this hypothesis by measuring the audibility of a target tone in a multitone masker after the presentation of precursors which, in some conditions, were made dissimilar to the masker by gating their components asynchronously. The precursor and the following sound were presented either to the same ear or to opposite ears. In either case, we found no significant difference in the amount of enhancement produced by synchronous and asynchronous precursors. In a second experiment, listeners had to judge whether a synchronous multitone complex contained exactly the same tones as a preceding precursor complex or had one tone less. In this experiment, listeners performed significantly better with synchronous than with asynchronous precursors, showing that asynchronous precursors were poorer perceptual templates of the synchronous multitone complexes. Overall, our findings indicate that precursor-induced auditory enhancement cannot be fully explained by the strategic use of the precursor as a template of the following masker. Our results are consistent with an explanation of enhancement based on selective neural adaptation taking place at a central locus of the auditory system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation / methods
  • Adult
  • Analysis of Variance
  • Audiometry, Pure-Tone
  • Auditory Threshold*
  • Female
  • Humans
  • Judgment
  • Male
  • Perceptual Masking*
  • Psychoacoustics
  • Young Adult

Grants and funding

This work was supported by a grant from the Agence Nationale de la Recherche (www.agence-nationale-recherche.fr; LEAP, Programme Blanc 2010). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.