Spatially mediated release from auditory masking in an anuran amphibian

✍ Scribed by Joshua J. Schwartz; H. Carl Gerhardt

• Book ID: 104657077
• Publisher: Springer
• Year: 1989
• Tongue: English
• Weight: 544 KB
• Volume: 166
• Category: Article
• ISSN: 0340-7594
• DOI: 10.1007/bf00190207

✦ Synopsis

1. The acoustic environment in which many species of frogs must communicate is characterized by high levels of background noise. Because the anuran auditory system is directionally sensitive, spatial cues should be useful in enhancing the ability of these animals to detect and localize calling conspecifics under such conditions.

2. We presented female green treefrogs, Hyla cinerea, with synthetic conspecific advertisement and aggressive calls in the presence of background broadband noise to assess the importance of directional information in signal detection, discrimination and localization.

3. We found that angular separation of call and noise sources facilitated a release from masking; females which failed to orient towards and approach speakers broadcasting calls positioned adjacent to a noise source did so when the noise sources were separated from the speakers by 45 ~ or 90 ~ . We estimate the improvement in signal-to-noise ratio with separation to be 3 dB or less. This increase was insufficient to facilitate discrimination between advertisement and aggressive calls.