As always Matthew Connell tells it best:
What makes the microphone especially significant is that it was signed by ten of the dignitaries officiating at the launch, including the NSW Premier Jack Lang, NSW Governor Philip Game and the Bridge’s Chief Engineer, JJC Bradfield.
Thanks to this simple device we are able to hear their voices today and witness the unveiling of a great Aussie icon, the Sydney Harbour Bridge, which symbolised progress, pride and hope for people at a time of great economic depression. Two months after the signatures were engraved on the microphone, Governor Philip Game sacked the Lang Government after Lang decided to default on loan repayments to the Commonwealth in favour of spending to stimulate the New South Wales economy. ..
Note: A big thank you to Mitchell Library, State Library of NSW who provided some of the images used in the youtube clip and to the National Film and Sound Archive’ & ‘Australianscreen Online’ who kindly provided the footage.