This Idea starts by pointing out the existence of a "speaker"
technology that uses ultrasonics (produces sounds that cannot
heard). See the first link. The ultrasound interacts with the
in such a way that the air becomes the source of the sound --
more, a particular point in the air
can be the source of the
So, equip a podium with a hidden ultrasound speaker system,
that the ultrasound waves are aimed at the microphone(s) on
podium. Audible sound would be produced in the air just next to
Your victim steps up to the podium to make a speech. He or she
positions his or her mouth near the microphone(s) on the
and he or she has ears that are not near the microphone(s).
you activate your ultrasound beam, he or she will not be able to
hear the sounds produced --but the microphone(s) on the podium
will hear those sounds.
So, you have secretly recorded many prior speeches made by
victim, and have edited your recordings appropriately, into
bites you can individually select from your remote-control panel
for the ultrasonic speaker system built into the podium.
Whenever the person speaking pauses to take a breath, you have
an opportunity to put additional words into his or her mouth --
they will be his or her own words, too!