Keegan Eveland¹ – kevelan1@jhu.edu
Bluesky: keeganeveland
Instagram: @keveland3

Capshaw G.^1,2*
Lauer, A. ^2,3,4
Moss, C.F.^1,3,5,6

1. Department of Psychological and Brain Sciences
   Johns Hopkins University
   Baltimore, MD, 21218
2. Department of Otolaryngology-Head and Neck Surgery
   Johns Hopkins University School of Medicine
   Baltimore, MD, 21205
3. The Solomon H. Snyder Department of Neuroscience
   Johns Hopkins University School of Medicine
   Baltimore, MD, 21205
4. Center for Functional Anatomy and Evolution
   Johns Hopkins University School of Medicine
   Baltimore, MD, 21205
5. Department of Mechanical Engineering
   Whiting School of Engineering
   Johns Hopkins University
   Baltimore, MD, 21218
6. Kavli Neuroscience Discovery Institute
   Johns Hopkins University
   Baltimore, MD, 21218

*Co-first author

Popular version of 2aAB8 – Noise-induced hearing loss susceptibility in the short-tailed fruit bat (Carollia perspicillata)
Presented at the 190th ASA Meeting
Read the abstract at https://eppro01.ativ.me/web/index.php?page=Session&project=ASASPRING2026&id=4082866

–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–

Hearing is crucial to many animal species that use sound to navigate, communicate, and avoid predators. Despite its importance, hearing in many animals is damaged by exposure to loud sounds. One exception is the echolocating bat, an animal that navigates in the dark using sound alone. While some vertebrates like fish and birds can regenerate the sensory cells that support hearing, mammals cannot, and hearing loss, caused by aging and exposure to loud noise, is common among mammals. This is what makes bats an intriguing case: bats can emit extremely loud ultrasonic calls (110 – 140 dB), the equivalent of a rock concert, yet some species show exceptional resistance to both age-related and noise-induced hearing loss.

However, not all bats are equally resistant to hearing loss; the ability to maintain hearing after noise exposure and into old age appears to reflect the degree of reliance on hearing for survival. For example, the big brown bat (Eptesicus fuscus), uses its hearing to hunt insects and is more resistant to both age-related and noise-induced hearing loss than the Egyptian fruit bat (Rousettus aegyptiacus), a frugivorous species that relies more heavily on vision for navigation and loses its hearing with age. This raises the question: What mechanisms make some bat species more resistant to hearing loss than others?

In this study, we examined noise susceptibility in the short-tailed fruit bat (Carollia perspicillata), which represents an interesting middle ground between these two species. Like the big brown bat, short-tailed fruit bats rely primarily on echolocation for navigation. However, like the Egyptian fruit bat, it feeds mainly on fruit and can supplement echolocation with other senses such as smell during foraging.

We hypothesize that short-tailed fruit bats maintain their hearing sensitivity even after exposure to loud noise, given their reliance on echolocation for navigation. To test this, we measured the bats’ hearing before and after one hour of exposure to intensely loud, 110 dB noise. We used two complementary methods: auditory brainstem responses, which assess auditory nerve and brainstem responses to sound, and otoacoustic emissions, which evaluate the functionality of the sensory cells that support cochlear amplification in the inner ear.

Our preliminary results show no long-term hearing damage following noise exposure, suggesting that short-tailed fruit bats possess protective mechanisms to preserve their most critical sense. These findings strengthen evidence that echolocation-dependent bats protect their hearing against noise damage better than those that primarily rely on other senses (such as vision). Understanding the biological mechanisms underlying this protection could have implications beyond bats and may reveal new strategies for preventing noise-induced hearing loss in other species.