What did Ariel trade to become human in Disney's "Little Mermaid"?

What did Ariel trade to become human in Disney's "The Little Mermaid"? She traded her beautiful voice. The sea witch Ursula magically removes Ariel's voice and stores it in a glowing nautilus shell as payment for transforming the mermaid into a human.

The deal is temporary at first. Ariel receives human legs for three days and must receive a kiss of true love from Prince Eric before the deadline. If she fails, she will return to the sea and belong to Ursula. Because Ariel cannot speak, Eric does not initially realize that she is the mysterious girl whose singing voice saved him after the shipwreck.

The voice is more than a physical payment: it becomes Ursula's weapon. Ursula later transforms into the human Vanessa and uses Ariel's stolen voice to enchant Eric. In the 1989 animated film, breaking the shell restores Ariel's voice and helps Eric recognize her. The 2023 live-action remake keeps the central bargain while changing some surrounding details.