iChat can sometimes get a bit noisy with notifications about buddies becoming available and not. All notification sounds and alerts for iChat are handled in the "Preferences" screen for the iChat application, under the "Alerts" tab.
- Open the iChat application.
- Go under the "iChat" menu to "Preferences..."
- Click on the "Alerts" tab.
- Use the "Event" pulldown menu to select the event type that you want to modify.
- Check or uncheck the checkboxes for the various alert types as you see fit.
