The Loudspeaking Telephone (LST) is a completely self-contained battery-powered communication unit that provides loudspeaker paging and handset party line conversation over a twisted telephone line.
Installation and maintenance are simple due to
the single plug-in amplifier board and the battery power supply used in the LST. The mode of
operation is also simple, greatly improving ambient noise rejection. An anti-side tone
circuit provides improved reception, particularly in areas with high ambient noise, and individual volume controls are provided for the speaker and handset receiver. The audio is of high quality; voices sound clear and natural, not harsh or metallic.