Summary
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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.
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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.
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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.
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References
Blauert J (1983) Spatial hearing. The psychophysics of human sound localization. 2nd Edition. MIT Press, Cambridge, Massachusetts
Chapman CJ, Johnstone ADF (1974) Some auditory discrimination experiments on marine fish. J Exp Biol 61:521–528
Cherry EC (1953) Some experiments on the recognition of speech, with one and with two ears. J Acoust Soc Am 25:975–979
Chung SH, Pettigrew A, Anson M (1978) Dynamics of the amphibian middle ear. Nature 272:142–147
Durlach NI, Colburn HS (1978) Binaural phenomena. In: Carterette EC, Friedman MP (eds) Handbook of perception. Vol. IV. Hearing. Academic Press, New York, pp 365–466
Ebata M, Sone T, Nimura T (1968) Improvement of hearing ability by directional information. J Acoust Soc Am 43:289–297
Ehret G, Gerhardt HC (1980) Auditory masking and effects of noise on responses of the green treefrog (Hyla cinerea) to synthetic mating calls. J Comp Physiol 141:13–18
Fay RR, Feng AS (1987) Directional hearing among nonmammalian vertebrates. In: Yost WA, Gourevitch G (eds) Directional hearing. Springer, Berlin Heidelberg New York, pp 179–213
Feng AS, Shofner WP (1981) Peripheral basis of sound localization in anurans. Acoustic properties of the frog's ear. Hearing Res 5:201–216
Flanagan JL, Watson BJ (1966) Binaural unmasking of complex signals. J Acoust Soc Am 40:456–468
Gerhardt HC (1974) The significance of some spectral features in mating call recognition in the green treefrog (Hyla cinerea). J Exp Biol 61:229–241
Gerhardt HC (1978a) Discrimination of intermediate sounds in a synthetic call continuum by female green treefrogs. Science 199:1089–1091
Gerhardt HC (1978b) Mating call recognition in the green treefrog (Hyla cinerea): the significance of some fine-temporal properties. J Exp Biol 74:59–73
Gerhardt HC (1982) Sound pattern recognition in some North American treefrogs (Anura: Hylidae): implications for mate choice. Am Zool 22:581–595
Gerhardt HC (1987) Evolutionary and neurobiological implications of selective phonotaxis in the green treefrog, Hyla cinerea. Anim Behav 35:1479–1489
Gerhardt HC (1989) Acoustic pattern recognition in anuran amphibians. In: Hulse S, Dooling R (eds) The comparative psychology of audition. Erlbaum, pp 175–197
Gerhardt HC, Daniel RE, Perrill SA, Schramm S (1987) Mating behaviour and male mating success in the green treefrog. Anim Behav 35:1490–1503
Gerhardt HC, Klump GM (1988) Masking of acoustic signals by the chorus background in the green treefrog: a limitation on female choice. Anim Behav 26:1247–1249
Hawkins AD, Sand O (1977) Directional hearing in the median vertical plane by the cod. J Comp Physiol 122:1–8
Levitt H, Rabiner LR (1967) Binaural release from masking for speech and gain in intelligibility. J Acoust Soc Am 42:601–608
Michelsen AM, Jørgensen M, Christensen-Dalsgaard J, Capranica RR (1986) Directional hearing of awake, unrestrained treefrogs. Naturwissenschaften 73:682
Moss CF, Simmons AM (1986) Frequency selectivity of hearing in the green treefrog, Hyla cinerea. J Comp Physiol A 159:257–266
Narins PM, Zelick R (1988) The effects of noise on auditory processing and behavior in amphibians. In: Fritszch B, Wilczynski W, Ryan M, Hetherington T, Walkowiak W (eds) The evolution of the amphibian auditory system. John Wiley & Sons, New York, pp 511–536
Oldham RS, Gerhardt HC (1975) Behavioral isolating mechanisms of the treefrogs Hyla cinerea and H. gratiosa. Copeia 1975:223–231
Rheinlaender J, Walkowiak W, Gerhardt HC (1981) Directional hearing in the green treefrog: a variable mechanism? Naturwissenschaften 68:430–431
Schwartz JJ, Wells KD (1983) The influence of background noise on the behavior of a neotropical treefrog, Hyla ebraccata. Herpetologica 39:121–129
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Schwartz, J.J., Gerhardt, H.C. Spatially mediated release from auditory masking in an anuran amphibian. J Comp Physiol A 166, 37–41 (1989). https://doi.org/10.1007/BF00190207
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DOI: https://doi.org/10.1007/BF00190207