Glossary beginning with E

Click one of the letters above to go to the page of all terms beginning with that letter.



"In the case of sexual advertisement sig- nals, the intended receivers are prospective mates, usually female conspecifics. Other receivers can also detect and respond to signals even if there was no selection on the sender to communicate with them. We refer to these receivers as eavesdroppers or unintended receivers. It is important to note that the terms intended and unintended should not imply intention- ality but instead refer to hypotheses about the selection forces that favored the evolution of these signals. With few exceptions, senders and receivers do not communicate in a private channel. The world is populated by unin- tended receivers, eavesdroppers who are attendant to the signals of senders, often to the demise of senders." [1]


Synonyms: unintended receiverunintended receiver


"(pronounced eck'eem) A first-order assemblage of syllables." [1]



"A first-order assemblage of echemes." [1]


echte Gehörsinn

"True sense of hearing", defined by von Buddenbrock (1937) [1] as a sense detceted by a resonating organ. 

"Wir werden einen Gehorsinn nur dann als bewiesen ansehen, wenn sich nachweisen lasst, dass das betreffende Sinnesorgan seiner Struktur nach spezifisch auf die Wahrnehmung von Schallwellen eingestellt ist. Das Kriterium des Gehorsinns ist daher das besonders ausgebildete Gehororgan, welches als charac- terisches Element in stets wiederkehrende Weise eine oder mehrere Membranen besitzt, die zum Mitschwingen durch Hesonanz befahigt sind.” [1]

This distinction between hearing and other vinratory senses, such as touch, is dismissed as anthropocentric by Pumphrey [2] : "Such a definition is clearly founded on the human analogy. The first sentence seems to imply that there is some fundamental distinction between sound waves and other mechanical stimuli, presumably on the grounds that touch and hearing are distinct in man, for the assumption can hardly be maintained in the face of the evidence bearing on the evolution of sound receptors either in vertebrate or other animals. But the second sentence goes even further. The final criterion of an auditory organ is not its specific sensitivity to sound waves, but a resemblance in certain arbitrary structural particulars to the human ear. If this criterion be accepted, fish are deaf by definition ... and only those insects with tympanic organs can hear. It is then necessary to invent an other sense, sensitivity to vibrations or Erschütterungssinn to explain the responsiveness to sound of animals which have no echter Gehorsinn."


  1. von Buddenbrock WD. Grundiss der vergleichenden Physiologie. Berlin: Borntraeger; 1937.
  2. Pumphrey RJ. Hearing in Insects. Biological Reviews. 1940;15(1):107 - 132. Available at:

Equal error rate

elementary waveform

"The hypothetical continuous wave-form to which any given wave-train emitted by an animal approximates; the basic signal." [1]


  1. Broughton WB. Glossarial Index. In: Acoustic Behavior of Animals. Acoustic Behavior of Animals. Elsevier; 1963.

Synonyms: elementary vibration


Time devised by von Buddenbrock [1] for animals that can detect vibration without a resonant organ (i.e. those without echte Gehörsinn).

This distinction is criticised by Pumphrey [2] : "This invention has had unfortunate consequences, because of the tendency to regard sensitivity to vibrations as a special kind of touch sense in quite a separate category from true hearing instead of regarding it as including true hearing, which would be both logical and consistent with what is known of the evolution of hearing organs."


  1. von Buddenbrock WD. Grundiss der vergleichenden Physiologie. Berlin: Borntraeger; 1937.
  2. Pumphrey RJ. Hearing in Insects. Biological Reviews. 1940;15(1):107 - 132. Available at:

Go to top

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith