Method of detecting the operation of a device for transmitting voice signals between two equipment items so that at least one of the equipment items can send a voice signal and the other equipment item can receive this voice signal, the equipment items being linked by a wireless transmission chain, the method comprising, during a voice signal transmission phase, the steps of: detecting on the sending equipment item a presence of a voice signal on transmission, and generating in response a voice presence on transmission signal; detecting on the receiving equipment item a presence or an absence of a voice signal on reception, and generating in response a signal indicating voice on reception; transmitting the signal indicating voice on reception from the receiving equipment item to the sending equipment item; comparing in the sending equipment item the voice presence on transmission signal and the signal indicating voice on reception, and triggering an alarm if the compared signals are not consistent.