When Mac OS 7.5.3 was released, the Sound control panel and Monitors control panel were merged into one (and for users of Mac OS 7.5.2, the Sound & Displays control panel was removed. Mac OS 7.5.3's replacement control panel, the Monitors & Sound control panel, merged the Sound and Monitors (separate) control panels, but did not feature a Record button. The Record button is hidden away in SimpleSound.
SimpleSound is accessible under the Apple menu. Users can pick a default system alert sound, remove alert sounds and also add (record) alerts of their own. To record sounds, a compatible microphone is required.
SimpleSound can also, via its Open command, open sound files and QuickTime movies (soundtrack only).
SimpleSound is not available in Mac OS X. The only way to record a sound in Mac OS X without resorting to third-party software is to record in iMovie. Beginning with QuickTime 7 Pro, you can also record sounds directly in the QuickTime Player.