How do frogs, birds, and lions produce sounds using airflow?

In the study of animal behaviour, sound production is a vital means of communication that relies on specialized anatomical structures to manipulate airflow.

Frogs

Frogs produce species-specific calls by cycling air between their lungs and buccal cavity (mouth). Unlike many other vertebrates, they do not expel air to vocalize; instead, they pass it back and forth over their vocal cords. The resulting vibrations are amplified by one or more vocal sacs, which serve as resonating chambers.123

Birds

Birds utilize a specialized organ called the syrinx, located at the base of the trachea where it divides into the bronchi. Sound is initiated when air from the lungs causes membranes within the syrinx to vibrate. Many birds, particularly songbirds, can control the left and right sides of the syrinx independently, allowing them to produce two distinct voices simultaneously.24

Lions

As mammals, lions produce vocalizations using the larynx, a structure situated at the top of the trachea. Sound is generated when air expelled from the lungs moves up the trachea and forces the vocal cords to vibrate. These raw sounds are then resonated and filtered through the upper cavities of the throat and mouth.23