Phase evaluation in hypothetical receivers simulating ranging in bats.

Area of Science:

• Bioacoustics
• Neuroethology
• Auditory Neuroscience

Background:

• Bats, such as Eptesicus fuscus, utilize echo delay discrimination for perceiving their environment.
• Previous research suggested a coherent cross-correlation receiver model based on psychometric curve dips in bat hearing experiments (Simmons 1979).

Purpose of the Study:

• To investigate alternative computational models for echo delay discrimination in bats.
• To explore receiver configurations that do not rely on coherent signal phase evaluation.

Main Methods:

• Computer simulations were employed to model auditory processing in bats.
• Simulations tested alternative receiver configurations, including neuronal filters with envelope-processing.

Main Results:

• Alternative receiver configurations, particularly those using envelope-processing, can produce a more pronounced dip in psychometric curves.
• These alternative models demonstrate increased robustness against noise compared to coherent cross-correlation models.

Conclusions:

• The dip in psychometric curves during echo delay discrimination may be explained by receiver models other than coherent cross-correlation.
• Neuronal filter banks processing signal envelopes offer a viable alternative hypothesis for bat auditory processing.
• Further behavioral experiments are recommended to differentiate between proposed auditory receiver models.