Summary
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1.
When appropriate synthetic call notes were broadcast to calling maleEleutherodactylus coqui in their natural habitat, the frogs responded by dropping the second note of their advertisement call. Broadband noise was used to mask the synthetic call notes, enabling an ‘effective critical ratio’ (ECR) to be derived.
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2.
Two classes of masking functions were found: monotonically decreasing masking functions and peaked masking functions. Two hypotheses are presented to account for the existence of these distinct functional classes.
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3.
The ECR forE. coqui was a function of the stimulus tone level used for its determination. At the lowest level (65 dB SPL), the ECR at 1 kHz was 31 dB.
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4.
Synthetic call notes were presented in noise of various bandwidths but of constant total power. The ‘effective critical band’ (ECB) at 1 kHz forE. coqui in its natural habitat was estimated to be 500 Hz.
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5.
These results are discussed in relation to the adaptations ofE. coqui for species-specific communication in a highly noisy environment.
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Abbreviations
- ECB :
-
effective critical band
- ECR :
-
effective critical ratio
- FET :
-
field effect transistor
- MDMF :
-
monotonically decreasing masking function
- PMF :
-
peaked masking function
- SPL :
-
sound pressure level
- S/N :
-
signal-to-noise ratio
- eq :
-
equalization
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Narins, P.M. Effects of masking noise on evoked calling in the Puerto Rican coqui (Anura: Leptodactylidae). J. Comp. Physiol. 147, 439–446 (1982). https://doi.org/10.1007/BF00612008
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DOI: https://doi.org/10.1007/BF00612008