The Collaborative International Dictionary of English v.0.48:

Telephony \Te*leph"o*ny\, n.
   The art or process of reproducing sounds at a distance, as
   with the telephone.
   [1913 Webster]

WordNet (r) 3.0 (2006):

telephony
    n 1: transmitting speech at a distance [syn: telephone,
         telephony]

The Free On-line Dictionary of Computing (30 December 2018):

telephony

    Communication, often two-way, of spoken
   information, by means of electrical signals carried by wires
   or radio waves.  The term was used to indicate transmission of
   the voice, as opposed to telegraphy (done in Morse code
   and usually called "continuous wave" or CW transmission),
   radio teletypewriter (RTTY) transmission (also called FSK for
   "Frequency Shift Keying", the modulation scheme used by such
   machines), and later, facimile.

   (1995-03-14)