moof

Lowing and barking (it’s claimed to be a mixture of the lowing of a cow and the barking of a dog) as you’d expect to hear from Clarus (from the original dogcow identified by Scott ‘Zz’ Zimmerman, named Clarus by Mark ‘The Red’ Harlan in 1987. See this brief history).

Sosumi

Alert (it was an alert sound introduced in 1991) heard in the battle between two Apples (it was a defiant pun on Apple Computer’s use of music in its products, in conflict with Apple Corps’ claimed trademark for the music of the Beatles) was renamed in Big Sur (when it was replaced by Sonumi, although it’s still named Sosumi in /System/Library/Sounds).

Chimes of Death

Arpeggio (it was originally an upward major arpeggio) or shattering glass (later models made the sound of glass being shattered) heard with a Sad Mac (displayed at the same time to indicate a severe problem that prevents normal startup in a Classic Mac).

They are sounds distinctive to Macs.