Orca availability from the bongo drum sound onwards seems to be the intended Ubuntu design principle for live images according to this citation from the Ubuntu Accessibility Wiki: "When you boot the live CD, you should hear a bongo drum sound. At this point, you can go ahead and enable Orca. Once again, the keyboard shortcut Alt + Super + S is used to enable orca. Orca should start speaking, and from this point you can select your language, and either boot into a live Ubuntu desktop by selecting the "Try Ubuntu" push button, or you can elect to install Ubuntu by selecting the "Install Ubuntu" push button."
Orca availability from the bongo drum sound onwards seems to be the intended Ubuntu design principle for live images according to this citation from the Ubuntu Accessibility Wiki: "When you boot the live CD, you should hear a bongo drum sound. At this point, you can go ahead and enable Orca. Once again, the keyboard shortcut Alt + Super + S is used to enable orca. Orca should start speaking, and from this point you can select your language, and either boot into a live Ubuntu desktop by selecting the "Try Ubuntu" push button, or you can elect to install Ubuntu by selecting the "Install Ubuntu" push button."