The Airbus has 2 speakers, located at the end of the main instrument panel. They allow the pass through of audio such as ATC from the ACP, and also aural alerts or EGPWS (Enhanced Ground Proximity Warning System).
The Airbus Alpine Speakers are rated at 15 ohms impedance and require 15 watts to operate
The speaker volume can be independently controlled by a knob on the PFD / ND panel.
The speakers are wired to also allow any aural and system alerts to override the speaker volume knob.
The next step will be to examine the circuit diagrams closely and attempt to output a computer sound card to the device.
Aircraft Schematic Manual (23-51-02), educational use only
(Thank you James and David)
Soarbywire 
Hi Ben, thank you very much for the Pictures! Great Topic! Could you tell the Diameter of the Speaker and the measures of the housing? Best regards, Marco
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