[Top] [All Lists]

New bioacoustic article in J. Comp Physiol. A

Subject: New bioacoustic article in J. Comp Physiol. A
From: "Sonja Amoser" <>
Date: Sun, 17 Feb 2008 19:21:34 +0100
Albert S. Feng and Peter M. Narins (2008): Ultrasonic communication in
concave-eared torrent frogs ( Amolops tormotus ). J. Comp. Physiol. A
194(2), 159-167.

Abstract: The concave-eared torrent frogs (Amolops tormotus) have highly
unusual ear morphology-in males the eardrums are embedded deep inside ear
cavities. In collaboration with our colleagues we investigated the
functional significance of this morphological feature in hearing. Sound
recordings in the field showed that males of A. tormotus produce diverse
bird-like melodic calls with pronounced frequency modulations and non-linear
phenomena (e.g., frequency jumps, different orders of subharmonics, and
chaos) that often contain spectral energy in the ultrasonic range. The
audible as well as the ultrasonic components of the species call could
effectively evoke males' vocal responses, demonstrating that they can hear
and respond to ultrasound. Electrophysiological recordings from the auditory
midbrain confirmed the ultrasonic hearing capacity of these frogs. The
recessed tympana and extremely thin tympanic membranes are adaptations for
hearing ultrasound-this sensitivity may have evolved in response to the
intense, predominately low-frequency ambient noise from local streams.
Finally, results from the isolated laryngeal preparation in euthanized frogs
revealed that the origin of call complexity and diversity lies with having a
vocal system with nonlinear properties.

For reprints please contact Albert S. Feng (Email: 

Nobuo Suga (2008): Role of corticofugal feedback in hearing. J. Comp.
Physiol. A 194(2),169-183.

Abstract: The auditory system consists of the ascending and descending
(corticofugal) systems. The corticofugal system forms multiple feedback
loops. Repetitive acoustic or auditory cortical electric stimulation
activates the cortical neural net and the corticofugal system and evokes
cortical plastic changes as well as subcortical plastic changes. These
changes are short-term and are specific to the properties of the acoustic
stimulus or electrically stimulated cortical neurons. These plastic changes
are modulated by the neuromodulatory system. When the acoustic stimulus
becomes behaviorally relevant to the animal through auditory fear
conditioning or when the cortical electric stimulation is paired with an
electric stimulation of the cholinergic basal forebrain, the cortical
plastic changes become larger and long-term, whereas the subcortical changes
stay short-term, although they also become larger. Acetylcholine plays an
essential role in augmenting the plastic changes and in producing long-term
cortical changes. The corticofugal system has multiple functions. One of the
most important functions is the improvement and adjustment (reorganization)
of subcortical auditory signal processing for cortical signal processing.^

For reprints please contact Nobuo Suga (Email: 

Kind regards

Sonja Amoser

<Prev in Thread] Current Thread [Next in Thread>
  • New bioacoustic article in J. Comp Physiol. A, Sonja Amoser <=

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the Bioacoustics-L mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU