Acoustic basis of directional acuity in laboratory mice

Research output: Contribution to journalArticle

Abstract

The acoustic basis of auditory spatial acuity was investigated in CBA/129 mice by relating patterns of behavioral errors to directional features of the head-related transfer function (HRTF). Behavioral performance was assessed by training the mice to lick a water spout during sound presentations from a "safe" location and to suppress the response during presentations from "warning" locations. Minimum audible angles (MAAs) were determined by delivering the safe and warning sounds from different locations in the inter-aural horizontal and median vertical planes. HRTFs were measured at the same locations by implanting a miniature microphone and recording the gain of sound energy near the ear drum relative to free field. Mice produced an average MAA of 31° when sound sources were located in the horizontal plane. Acoustic measures indicated that binaural inter-aural level differences (ILDs) and monaural spectral features of the HRTF change systematically with horizontal location and therefore may have contributed to the accuracy of behavioral performance. Subsequent manipulations of the auditory stimuli and the directional properties of the ear produced errors that suggest the mice primarily relied on ILD cues when discriminating changes in azimuth. The MAA increased beyond 80° when the importance of ILD cues was minimized by testing in the median vertical plane. Although acoustic measures demonstrated a less robust effect of vertical location on spectral features of the HRTF, this poor performance provides further evidence for the insensitivity to spectral cues that was noted during behavioral testing in the horizontal plane.

Original languageEnglish (US)
Pages (from-to)633-645
Number of pages13
JournalJARO - Journal of the Association for Research in Otolaryngology
Volume12
Issue number5
DOIs
StatePublished - Oct 1 2011

Keywords

  • head-related transfer function
  • inter-aural level differences
  • minimum audible angle
  • spatial acuity
  • spectral cues

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Sensory Systems

Fingerprint Dive into the research topics of 'Acoustic basis of directional acuity in laboratory mice'. Together they form a unique fingerprint.

  • Cite this