Diagnostic method of electrical equipment which comprises: a processing unit; at least one internal microphone, and/or means for connecting to at least one external microphone; electrical components other than microphones or speakers; the diagnostic method being implemented at least partially in the processing unit and comprising the steps of: acquiring a received audio signal (Sar) produced from capturing an ambient sound signal (Sa), by the at least one internal microphone or by the at least one external microphone; producing monitoring parameters from the received audio signal, which are representative of an interfering sound signal (Sp) comprised in the ambient sound signal and emitted by at least one of the electrical components; detecting a sound anomaly resulting from a current or future failure of at least one electrical component of the electrical equipment from the monitoring parameters, the method being characterized in that it further comprising the steps: of detecting if the electrical equipment, at the time of the acquisition step, is in the process of emitting a useful sound signal (Su), which comprises sounds voluntarily emitted; if this is the case, of applying the received audio signal (Sar) at the input of an acoustic echo cancellation module, to produce a resulting signal (Sr), the monitoring parameters being obtained from the resulting signal. a processing unit; at least one internal microphone, and/or means for connecting to at least one external microphone; electrical components other than microphones or speakers; the diagnostic method being implemented at least partially in the processing unit and comprising the steps of: acquiring a received audio signal (Sar) produced from capturing an ambient sound signal (Sa), by the at least one internal microphone or by the at least one external microphone; producing monitoring parameters from the received audio signal, which are representative of an interfering sound signal (Sp) comprised in the ambient sound signal and emitted by at least one of the electrical components; detecting a sound anomaly resulting from a current or future failure of at least one electrical component of the electrical equipment from the monitoring parameters, acquiring a received audio signal (Sar) produced from capturing an ambient sound signal (Sa), by the at least one internal microphone or by the at least one external microphone; producing monitoring parameters from the received audio signal, which are representative of an interfering sound signal (Sp) comprised in the ambient sound signal and emitted by at least one of the electrical components; detecting a sound anomaly resulting from a current or future failure of at least one electrical component of the electrical equipment from the monitoring parameters, the method being characterized in that it further comprising the steps: of detecting if the electrical equipment, at the time of the acquisition step, is in the process of emitting a useful sound signal (Su), which comprises sounds voluntarily emitted; if this is the case, of applying the received audio signal (Sar) at the input of an acoustic echo cancellation module, to produce a resulting signal (Sr), the monitoring parameters being obtained from the resulting signal. of detecting if the electrical equipment, at the time of the acquisition step, is in the process of emitting a useful sound signal (Su), which comprises sounds voluntarily emitted; if this is the case, of applying the received audio signal (Sar) at the input of an acoustic echo cancellation module, to produce a resulting signal (Sr), the monitoring parameters being obtained from the resulting signal.