Elephant
Explanation
Sound waves are classified based on their frequency relative to the human hearing range (20 Hz to 20,000 Hz). Frequencies below 20 Hz are termed infrasonic (infrasound), while frequencies above 20,000 Hz are termed ultrasonic (ultrasound).
Analysis of Options:
- Bats, Dolphins, and Porpoises: These animals are well-known for producing and detecting ultrasound (frequencies greater than 20 kHz). They utilize these high-frequency waves for echolocation to navigate and hunt prey.
- Elephants: Elephants communicate using very low-frequency sounds known as infrasound (often as low as 14–16 Hz). Infrasonic waves have longer wavelengths, allowing them to travel long distances and pass around obstacles with less attenuation compared to high-frequency sounds. Other animals that use infrasound include rhinoceroses and whales.
Key Takeaway:
Infrasound (< 20 Hz) is produced by large animals like elephants and whales for long-distance communication, whereas Ultrasound (> 20 kHz) is used by bats and marine mammals for echolocation.