The Jargon File (version 4.4.7, 29 Dec 2003):

feep
 /feep/

    1. n. The soft electronic ?bell? sound of a display terminal (except for a
    VT-52); a beep (in fact, the microcomputer world seems to prefer beep).

    2. vi. To cause the display to make a feep sound. ASR-33s (the original
    TTYs) do not feep; they have mechanical bells that ring. Alternate forms: 
    beep, ?bleep?, or just about anything suitably onomatopoeic. (Jeff
    MacNelly, in his comic strip Shoe, uses the word ?eep? for sounds made by
    computer terminals and video games; this is perhaps the closest written
    approximation yet.) The term ?breedle? was sometimes heard at SAIL, where
    the terminal bleepers are not particularly soft (they sound more like the
    musical equivalent of a raspberry or Bronx cheer; for a close
    approximation, imagine the sound of a Star Trek communicator's beep lasting
    for five seconds). The ?feeper? on a VT-52 has been compared to the sound
    of a '52 Chevy stripping its gears. See also ding.


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

feep
breedle

   /feep/ 1.  The soft electronic "bell" sound of a display
   terminal (except for a VT-52); a beep (in fact, the
   microcomputer world seems to prefer beep).

   2. To cause the display to make a feep sound.  ASR-33s (the
   original TTYs) do not feep; they have mechanical bells that
   ring.  Alternate forms: beep, "bleep", or just about
   anything suitably onomatopoeic.  (Jeff MacNelly, in his comic
   strip "Shoe", uses the word "eep" for sounds made by computer
   terminals and video games; this is perhaps the closest written
   approximation yet.)  The term "breedle" was sometimes heard at
   SAIL, where the terminal bleepers are not particularly soft
   (they sound more like the musical equivalent of a raspberry or
   Bronx cheer; for a close approximation, imagine the sound of a
   Star Trek communicator's beep lasting for five seconds).  The
   "feeper" on a VT-52 has been compared to the sound of a '52
   Chevy stripping its gears.  See also ding.

   [Jargon File]