Bundled with the Macintosh Centris 660AV and Quadra 840AV. The Sound Effects extension adds sound effects options to the Sound control panel. After installation, open the Sound control panel and choose Effects from the pop-up menu. The Effects section of the control panel appears, showing another pop-up menu. Choose an effect from the pop-up menu. When you choose an item, the current alert sound plays with that effect. The effect you choose remains active for all sounds the computer plays until you restart the computer. At restart, the effect choice reverts to None. If you want to keep using a sound effect, you must choose it again. Note: When a sound effect is active, you can't change the sample rate in the Sound Out section of the control panel.