Cal took the microphone in his own hand to answer.
"Eight Keys to Eden"
Mark Irvin Clifton
He afterwards set up a paper of his own, then became telegraph operator, studied electricity, invented electric light, the electric pen, the telephone, microphone, phonograph, etc.
"A Biographical Dictionary of Freethinkers of All Ages and Nations"
Joseph Mazzini Wheeler
It was no larger than a pack of playing cards, and its sensitive microphone was incorporated right into the case.
"The Electronic Mind Reader"
John Blaine