One method I heard of preventing eavesdropping through windows is to play music in the air space between the window panes.
I glass installer once told me that they installed the windows at one of the intelligence agencies and that’s what they did.
One method I heard of preventing eavesdropping through windows is to play music in the air space between the window panes.
I glass installer once told me that they installed the windows at one of the intelligence agencies and that’s what they did.
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That would work if the gap between panes had your typical nitrogen fill... after all music/sound needs a transport mechanism... if there was a vacuum between the panes a laser microphone would likely work on the inner pane although you’d need a light color that can penetrate the outer pane cleanly which likely has some barrier to UV .. more than likely the speaker/sound source was directed or attached to the pane or frame of the window.