Can Bats Hear? 🦇Explore the Bat’s Extraordinary Senses

Can Bats Hear?

Answer at a Glance: Bats possess an extraordinary sense of hearing. As per the National Park Service, bats can detect sounds as high as 120,000 Hz, a range that surpasses most other mammals. Their hearing abilities are diverse, with some species relying on echolocation and others on passive hearing, making them truly unique in the animal kingdom.

Dive Deeper

• How Bats Hear: Echolocation and Passive Hearing
• Bat’s Hearing Sensitivity Compared to Other Mammals
• Anatomy That Supports Bat Hearing
• Bats Experience Age-Related Hearing Loss
• References

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How Bats Hear: Echolocation and Passive Hearing

Echolocation (Active Hearing)

Some bat species use their keen sense of hearing to both navigate and find food, a process known as echolocation. 

• How Echolocation Works:
  1. Bat emits a high-frequency sound (ultrasonic).
  2. Sound bounces off objects (like insects).
  3. Echo returns to the bat’s ears.
  4. Bat processes the echo to “see” its environment acoustically.
• Frequencies Used:
  • Range: 20 kHz to over 200 kHz.
  • Example:
    • Greater horseshoe bat: 83–86 kHz.
    • Big brown bat: 20–40 kHz.
  • Some species (like Rhinolophus) even modulate frequencies mid-call.
• Precision:
  • Can detect objects less than 0.1 mm apart.
  • Can distinguish between two targets only 6–10 microseconds apart in echo delay.

Passive Hearing (Listening to Environmental Sounds)

• Not all bats echolocate.
  • Megabats (fruit bats, such as Pteropus) don’t echolocate with their larynx, but they still have excellent hearing.
• Some bats (e.g., Plecotus auritus) can detect prey-generated sounds like moth wing flutters.

Bat’s Hearing Sensitivity Compared to Other Mammals

Mammal	Frequency Range (approx.)	Notes
Human	20 Hz – 20 kHz	Can’t hear ultrasonic sounds
Dog	40 Hz – 60 kHz	Hears higher than humans
Cat	48 Hz – 85 kHz	Sensitive to ultrasonic prey sounds
Bat	15 kHz – 200+ kHz	Most sensitive to ultrasonic frequencies
Dolphin	40 Hz – 150 kHz	Also uses echolocation, but underwater

Conclusion: Bats are among the top for ultrasonic hearing, but for low frequencies, other animals (like elephants or whales) outperform them.

Anatomy That Supports Bat Hearing

Ear Features

• Large pinnae (external ears) to collect sound.
• Tragus: A flap that helps localize the vertical direction of sound.
• Cochlea: Enlarged and highly specialized to resolve tiny differences in frequency and timing.
• Time resolution: Can detect echoes spaced less than 1 millisecond apart.

Research conducted by Chen Chiu and Cynthia Moss of the University of Maryland has demonstrated that the bat’s ears and a keen sense of hearing are instrumental to echolocation.  To test how the ears function in echolocation and hunting prey, the researchers deflected the tragus of six brown bats, discovering that the bat’s ability to capture prey dropped dramatically.  This experiment highlighted the crucial role of the tragus in the bat’s echolocation process, providing a deeper understanding of their anatomy and abilities.

Brain Processing

• The auditory cortex has dedicated areas for delay tuning, frequency discrimination, and motion tracking.

Bats Experience Age-Related Hearing Loss

Interestingly, bats experience age-related hearing loss similar to humans. Typically, age-related hearing loss begins at higher frequencies. This hearing is critical for echolocating bat species that require it to navigate through their habitat and capture prey. The onset of age-related hearing loss in bats may have significant implications for their ability to survive and hunt as they age.

References

• National Park Service – Everglades National Park – “Bats.”
• Neuweiler, Gerhard. The Biology of Bats. Oxford University Press, 2000.
• Suga, Nobuo. “Biosonar and Neural Computation in Bats.” Scientific American, vol. 262, no. 6, 1990, pp. 60–68.
• Simmons, J.A. (1973). The resolution of target range by echolocating bats. Journal of the Acoustical Society of America, 54(1), 157–173.
• Thomas, Jeanette A., et al. Echolocation in Bats and Dolphins. University of Chicago Press, 2004.
• University of Maryland – College of Behavioral and Social Sciences – “Project: The Role of Tragus in Echolocating Bat, Eptescus Fuscus.”
• Tarnovsky, Yifat Chaya, et al. “Bats Experience Age-related Hearing Loss (Presbycusis).” Life Science Alliance, vol. 6, no. 6, Mar. 2023, p. e202201847. https://doi.org/10.26508/lsa.202201847.

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