Attaching a callback to *all* buttons in an application

[Lance Capser <lmcapser bigfoot com>]

Greetings, Programs!

    I'm looking for a way to generically attach a callback routine to
    all the buttons in my app.  Specifically, I would like to play a
    sound to provide audible feedback that a button was pressed (for a
    touchscreen application).  I see that GNOME does this (sortof) in
    the audio preferences but I'm not quite sure how it's being done -
    it seems to narrow down specific types of widgets (toggle buttons,
    "Action" buttons, menu activation, etc).  Could anyone out there
    please provide a small explanation on how this works and how to
    implement it in my own program?  

Thanks in advance

Lance

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