Abstract: A software-controlled telephone tester permits untrained consumers to test telephone sets by connecting the line cord to the tester and following simple instructions which are sequentially displayed on a panel. Tests are automatically performed after each instruction to provide objective determinations of the operability of the telephone under test. Tested parameters which fall outside specification result in a failure indication. If the user fails to effect certain instructions properly, a "try again" instruction is generated. Transmission tests are effected automatically by placing the telephone earpiece and/or mouthpiece adjacent a transducer and transmitting at least one tone from the tester through the telephone and back to the tester. Preferrably a two-tone test is employed using a pair of the standard DTMF signalling tones so that transmission testing is effected using the same circuitry employed for DTMF dial testing.