TY - JOUR TI - How spatial release from masking may fail to function in a highly directional auditory system AU - Lee, Norman AU - Mason, Andrew C A2 - Carr, Catherine Emily VL - 6 PY - 2017 DA - 2017/04/20 SP - e20731 C1 - eLife 2017;6:e20731 DO - 10.7554/eLife.20731 UR - https://doi.org/10.7554/eLife.20731 AB - 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° to 90° 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. KW - Ormia ochracea KW - cocktail-party-problem KW - sound localization KW - mechanically coupled pressure receiver KW - song recognition KW - spatial release from masking JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -