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How spatial release from masking may fail to function in a highly directional auditory system

  1. Norman Lee  Is a corresponding author
  2. Andrew C Mason
  1. University of Toronto at Scarborough, Canada
Research Article
  • Cited 5
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Cite this article as: eLife 2017;6:e20731 doi: 10.7554/eLife.20731

Abstract

Spatial release from masking (SRM) occurs when spatial separation between a signal and masker decreases masked thresholds. The mechanically-coupled ears of Ormia ochracea are specialized for hyperacute directional hearing, but the possible role of SRM, or whether such specializations exhibit limitations for sound source segregation, is unknown. We recorded phonotaxis to a cricket song masked by band-limited noise. With a masker, response thresholds increased and localization was diverted away from the signal and masker. Increased separation from 6{degree sign} to 90{degree sign} did not decrease response thresholds or improve localization accuracy, thus SRM does not operate in this range of spatial separations. Tympanal vibrations and auditory nerve responses reveal that localization errors were consistent with changes in peripheral coding of signal location and flies localized towards the ear with better signal detection. Our results demonstrate that, in a mechanically coupled auditory system, specialization for directional hearing does not contribute to source segregation.

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Author details

  1. Norman Lee

    Integrative Behaviour and Neuroscience Group, Department of Biological Sciences, University of Toronto at Scarborough, Toronto, Canada
    For correspondence
    leen@umn.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6198-710X

  2. Andrew C Mason

    Integrative Behaviour and Neuroscience Group, Department of Biological Sciences, University of Toronto at Scarborough, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.

Funding

Natural Sciences and Engineering Research Council of Canada (Discovery Grant)

  • Andrew C Mason

Natural Sciences and Engineering Research Council of Canada (PGS D3)

  • Norman Lee

Ontario Graduate Scholarship

  • Norman Lee

Society for Integrative and Comparative Biology grants-in-aid of research

  • Norman Lee

Animal Behavior Society Student Grant

  • Norman Lee

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Catherine Emily Carr, University of Maryland, United States

Publication history

  1. Received: August 17, 2016
  2. Accepted: April 19, 2017
  3. Accepted Manuscript published: April 20, 2017 (version 1)
  4. Accepted Manuscript updated: April 24, 2017 (version 2)
  5. Accepted Manuscript updated: April 25, 2017 (version 3)
  6. Version of Record published: May 24, 2017 (version 4)

Copyright

© 2017, Lee & Mason

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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