Abstract: An electronic volume varying apparatus for producing a controlling signal to control an electronic volume in response to pulses from a manually operable pulse generator, wherein it is prevented, when incorporated in a cassette deck or the like, that a listener is surprised with a great sound volume after cancellation of a muting mode. A muting judging section outputs a memory disabling signal when a muting-on signal is supplied thereto, and a memory enabling/disabling device is interposed between a pulse counting device and a memory device of a controlling section and stops its outputting of pulse count data from the pulse counting device to the memory device in response to the memory disabling signal from the muting judging section. A method and apparatus which can accurately detect an input pulse from a manually operable pulse generator as well as a pulse switch which eliminates inadvertent outputting of a pulse are also disclosed.