![]() Most bat ears are tuned to hear their prey, and in this case, vampire bats prey on large animals that make low pitch breathing sounds. On the basis of these findings, it is suggested that vampire bats can memorize and classify complex acoustic features of prey-generated breathing sounds to facilitate the identification of prey animals that they have successfully fed on before. Numerical simulations show that while the human listeners relied on breathing-frequency information, the vampire bats appeared to recruit different acoustic parameters and to choose amongst these parameters depending on which provided the highest discriminative power. This exceptional performance is underlined by the inability of human listeners to match the vampire bats’ accomplishment under the most difficult experimental condition where the sounds had been recorded under physical strain. In the three-alternative, forced-choice setup, it spontaneously associates unknown breathing sounds with the subject who emitted them. The current behavioral study shows that the common vampire bat, Desmodus rotundus, is very sensitive to breathing sounds. To summarize, in the authors’ words: a common vampire bat’s ear Why do vampire bats have such good low frequency hearing? Check out this paper entitled “Classification of human breathing sounds by the common vampire bat, Desmodus rotundus“ These strange peaks indicate that vampire bats might have some kind of yet-undescribed mechanism that gives them improved low-frequency hearing. Then with even lower frequencies, the bat continues to lose sensitivity… until 2.4 kHz where, again, the sensitivity of the vampire ear jumps up again to another high point at about 2 kHz. So, interestingly, vampires can hear 4 kHz better than 5 kHz. Below that point, the sensitivity suddenly jumps up, beyond other bats. One piece of evidence for this is the fact that the hearing sensitivity of the common vampire at decreasing frequencies looks somewhat normal until it hits 5 kHz. Vampire bat sensitivity for low frequencies seems to be a special adaptation. While bats can’t hear bass, they could feel vibrations of intense low sounds with their bodies. In fact, common vampires have better low-frequency hearing than the Virginia opposum. Still, a vampire’s hearing limit is more than an octave lower than other Neotropical leaf-nosed bats. ![]() That means that when I’m holding a struggling vampire bat and talking to it in a quiet, soothing, and re-assuring voice, they hear none of that. They can’t hear that sound even when it is broadcast at 80 dB SPL (think really loud vacuum cleaner). See (er, hear):įor a bat, that is infrasonic, way too low even for a vampire bat. At 60 dB, a common vampire bat can hear sounds as low as 716 Hz. The authors of this study confirmed that- as far as we know- common vampires can hear the lowest frequencies of any bat, including the big Paleotropical fruit bats that don’t echolocate at all. What’s particularly unique about vampires, though, is not their high frequency hearing, but rather their low frequency hearing. This performance is on par with larger bats, but exceeded by smaller aerial insectivores*. If you strung wires throughout a room without light, vampires would be able to avoid wires as thin as 0.5 mm, albeit they might need several trials of practice before they can maneuver adeptly around 0.25 mm wires ( source). The echolocation ability of vampire bats is comparable with other bats. As you would expect, vampire bats have excellent hearing in the range in which they echolocate (about 70 kHz). They need this ultrasonic hearing of course to analyze the echoes of their biosonar calls. Anything above about 17 kHz starts to sound like weirdly uncomfortable silence to us, but a vampire bat can hear well up to 113 kHz. Vampires like other bats have excellent high frequency hearing.
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