Technical Information Security Surveys (TSCM) Counterespionage Consulting Services
for business & government, since 1978.
is not a new desire...
"The Whispering Telephone Mouthpiece makes all telephones private, enables you to talk at your desk or in your home in a whisper so that what you say cannot be heard by those around you.
The small cone inside of the mouthpiece so distributes and intensifies the voice that this is made possible, can be used on ant telephone and is endorsed by the telephone companies everywhere. Especially adapted for long distance use."
The S. & M. Electric Co. (Inc.) c.1900