* A deep, booming call: This is their most common vocalization and is often described as a "whoop" or "honk." It can be heard from a great distance and is used for communication between birds.
* A series of rapid clicks: These clicks are made by the bird's beak and are often used in courtship displays.
* A rasping sound: This sound is made by the bird's vocal chords and is often used as a warning call.
While not as common as the other sounds, the Great Indian Hornbill is also known to make:
* A hissing sound: This is used as a defensive mechanism.
* A croaking sound: This is used to attract mates.
Overall, the Great Indian Hornbill is a vocal bird that uses a variety of sounds for communication and other purposes.