Mariah Carey has signature use of the highest register of the human voice.
Mariah Carey . Referred to as the `` songbird supreme '' by the Guinness World Records , she has a five-octave vocal range , power , melismatic style and signature use of the whistle register . The whistle register ( also called the flute register or whistle tone ) is the highest register of the human voice , lying above the modal register and falsetto register .