[ tel-hahr-moh-nee-uh m ]
/ ˌtɛl hɑrˈmoʊ ni əm /
a musical keyboard instrument operating by alternating currents of electricity which, on impulse from the keyboard, produce music at a distant point via telephone lines.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for telharmonium
Just why the telharmonium has not made good its promises of popularity I do not know.Mark Twain, A Biography, 1835-1910, Complete|Albert Bigelow Paine