Inside Macintosh: Sound /

Chapter 2 - Sound Manager / Sound Manager Reference

Sound Manager Routines / Playing Sound Resources

SysBeep

You can use the SysBeep procedure to play the system alert sound.

PROCEDURE SysBeep (duration: Integer);

duration

The duration (in ticks) of the resulting sound. This parameter is ignored except on a Macintosh Plus, Macintosh SE, or Macintosh Classic when the system alert sound is the Simple Beep. The recommended duration is 30 ticks, which equals one-half second.

DESCRIPTION

The SysBeep procedure causes the Sound Manager to play the system alert sound at its current volume. If necessary, the Sound Manager loads into memory the sound resource containing the system alert sound and links it to a sound channel. The user selects a system alert sound in the Alert Sounds subpanel of the Sound control panel.

The volume of the sound produced depends on the current setting of the system alert sound volume, which the user can adjust in the Alert Sounds subpanel of the Sound control panel. The system alert sound volume can also be read and set by calling the GetSysBeepVolume and SetSysBeepVolume routines. If the volume is set to 0 (silent) and the system alert sound is enabled, calling SysBeep causes the menu bar to blink once.

SPECIAL CONSIDERATIONS

Because the SysBeep procedure moves memory, you should not call it at interrupt time.

SEE ALSO

For information on enabling and disabling the system alert sound, see the description of SndGetSysBeepState and SndGetSysBeepState on page 2-137. For information on reading or adjusting the system alert sound volume, see "Controlling Volume Levels" beginning on page 2-139.