This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
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How to | Find Out Why Mathematica Beeped
Mathematica usually works silently, giving output only when it has finished doing the calculations you asked for. However, Mathematica will produce an audible beep when the front end encounters an error.
This is a selection of examples from the complete "How to" screencast. »
Attempting to evaluate a text cell will produce a beep. Select this text cell and press Shift+Enter
Click for copyable input
To find out why Mathematica produced the beep, select HelpWhy the Beep?:
A window pops up telling you that Mathematica beeped because you tried to evaluate an unevaluatable cell:
Other actions that make Mathematica beep include trying to type with a cell bracket selected or using EditFind for something that is not in the current notebook.
    
To choose the actions that Mathematica will take when it encounters front end errors, open the Preferences menu.
If you are running Mac OS X, select Preferences from the Mathematica menu. If you are running Windows or Linux, select Edit Preferences:
On the Interface tab of the Preferences window, you can select the actions you prefer in the Message and Warning Actions section: