Interface Preferences

Display

• Ergonomic order of audio I/O buttons: Sets the Control Toolbar button order as: Pause, Play, Stop, Skip to Start, Skip to End, Record, rather than: Skip to Start, Play, Record, Pause, Stop, Skip to End.
• Show 'How to get Help' message at program start up: -- self-explanatory? --
• Meter/Waveform dB range: Sets the minimum displayed value of the Meter Toolbar, and of the vertical logarithmic scale in the Waveform (dB) track display (this display is enabled in the Track Drop-Down Menu). -60 dB is the default value. The chosen value affects the gradation ticks and values displayed on the meter, according to whether it is at default size or dragged out to give longer scales.
• Language: This drop-down menu changes the language of the menus and other on-screen text. Languages with unusual character sets require you to have the correct fonts installed on your system, otherwise the menus will display with ???? characters.
• Location of Manual:
  • "Local" is what most people will want: Audacity will show help in its built-in browser, using HTML files stored on your computer.
  • "From Internet" will always use the latest help files from the internet, opening your default browser to do this.

Behaviors

• Closing last window quits Audacity: Sets Audacity to quit when the last project window you are working with is closed. Unchecking this can be useful as it lets you use File > Close to close the last window and then create a new empty Project. To shut Audacity down with this preference unchecked, you must use File > Exit (on a Mac, Audacity > Quit Audacity) or the respective shortcut.
• Beep on completion of longer activities: Audacity makes a quiet system beep after completion of longer tasks. Visually impaired users may find this useful, though the beep may not be audible on all computers.

Modes

• CleanSpeech Mode: A customization of Audacity by Lynn Allan with limited menu options. It's mainly used for quick clean-up and MP3 export of a number of speech recordings, carried out as a batch process. The available effects in the "CleanSpeech" batch chain are limited to Fade In, Fade Out, Leveller, Noise Removal, Normalize, Stereo to Mono and Truncate Silence. A simple "MP3 Conversion" chain is also provided which has only a Normalize effect.

It is probably worth noting that all the Save menu items are missing from the File menu in this mode! It appears that the intent is to import files, process them, then export them without ever saving a project file. But if you close a dirty file you can still reach the Save dialog!

• To run a CleanSpeech or MP3 Conversion chain with CleanSpeech Mode enabled, click the special CleanSpeech button that is added to the right of the standard Control Toolbar. In the "Apply Chain" dialog that pops up, select one of the chains and apply it either to the current project or to files. If you apply the chain to files, these will be imported into Audacity for processing. The processed files are saved in a folder named "cleaned" that is created (if necessary) in the folder containing the original files. The original files are not altered. To edit the parameters for the chains, or to add a new one, click File > Edit Chains... .
  
  More information about CleanSpeech is available here.

Processing a batch chain is available to all users without enabling CleanSpeech Mode. The same CleanSpeech and MP3 Conversion chains are available, but you can add more effects to a chain when not in CleanSpeech Mode. Apply an existing chain at File > Apply Chain... and edit or add chains at File > Edit Chains....

I have not mentioned the import/export presets under File Menu as I don't understand what they do - they obviously don't relate to the chains or their parameters and even the CleanSpeech docs give no clue. - Gale
I can't figure this out either. The .csp file that is created by File > Export Cleanspeech Presets is not human-readable. - Bill