Functional aspects of anuran middle ear structures.

1. The opercular complex of amphibians functions to enhance perception of airborne environmental sounds below 1 KHz. 2. The columella and tympanum of frogs function in the perception of acoustic information above 1 KHz. 3. The opercular complex and amphibian papilla comprise the general hearing mechanism in amphibians. 4. The tympanum, columella and basilar papilla, present in totality only in frogs, are concerned with reproductive communication. 5. Interaction of the two systems in frogs provides a mechanism for enhancing input signal to noise ratio during chorusing. 6. Experimental determinations of acoustic perception in amphibians must be controlled for anaesthesia and forelimb disposition. The presence of anaesthesia or unnatural limb position can affect the animal's ability to perceive low frequency sounds by preventing normal opercularis function. The authors names are in alphabetical order. The sequence does not imply seniority.

[1]  M. Sachs.  Responses to Acoustic Stimuli from Single Units in the Eighth Nerve of the Green Frog , 1964 .

[2]  Coleman J. Goin,et al.  Introduction to herpetology , 1963 .

[3]  L. S. Frishkopf,et al.  Neural coding in the bullfrog's auditory system a teleological approach , 1968 .

[4]  B. Johnstone,et al.  Auditory function, communication, and the brain-evoked response in anuran amphibians. , 1970, The Journal of the Acoustical Society of America.

[5]  H. D. Potter,et al.  Patterns of acoustically evoked discharges of neurons in the mesencephalon of the bullfrog. , 1965, Journal of neurophysiology.

[6]  W. V. Bergeijk.  Observations on Models of the Basilar Papilla of the Frog's Ear , 1957 .

[7]  B. Kingsbury,et al.  The columella auris in amphibia , 1908 .

[8]  T. Monath.  The opercular apparatus of salamanders , 1965 .

[9]  C. Daniel Geisler,et al.  Peripheral Origin of Auditory Responses Recorded from the Eighth Nerve of the Bullfrog , 1966 .

[10]  E. Dunn.  The “opercularis” muscle of Salamanders , 1941 .

[11]  R. Capranica.  The evoked vocal response of the bullfrog- A study of communication by sound , 1966 .

[12]  J. J. Smith.  Hearing in terrestrial urodeles: a vibration-sensitive mechanism in the ear. , 1968, The Journal of experimental biology.

[13]  The Effect of Severing the Opercularis Muscle on Body Orientation of the Leopard Frog, Rana pipiens , 1969 .

[14]  S. N. Sedra,et al.  The ontogenesis of the sound conducting apparatus of the egyptian toad, bufo regularis reuss, with a review of this apparatus in salientia , 1959, Journal of morphology.

[15]  D. Wake.  Comparative osteology and evolution of the lungless salamanders , 1966 .

[16]  A. Romer.  The vertebrate body , 1971 .

[17]  Lawrence S. Frishkopf,et al.  Responses to Acoustic Stimuli from Single Units in the Eighth Nerve of the Bullfrog , 1963 .

[18]  L. S. Frishkopf,et al.  The inner ear of the bullfrog , 1964, Journal of morphology.