A hearing instrument for use by a user, comprising: a first microphone (M 1) for generation of a first microphone signal in response to receipt of sound, the first microphone (M 1) comprising a positive power supply terminal (V MIC1) and a negative power supply terminal; and a control and processing circuit comprising: a first audio input channel configured to receive the first microphone signal, a second audio input channel configured for receipt of an audio signal, a signal processor for receipt and processing of the first microphone signal and the audio signal according to a hearing loss of the user, a power supply configured to provide a first microphone supply voltage for the first microphone (M 1), a first controllable switch (SW 1) comprising a first switch control terminal, the first controllable switch (SW 1) configured to selectively connect the first microphone supply voltage to, and disconnect the first microphone supply voltage from, the first microphone (M 1) in accordance with a first switch control signal (Φ 1), and a first output port configured to provide the first switch control signal (Φ 1) to the first switch control terminal, characterized in that the signal processor is configured to set a logic state of the first output port based on at least one processing parameter used to process the first microphone signal. a first microphone (M 1) for generation of a first microphone signal in response to receipt of sound, the first microphone (M 1) comprising a positive power supply terminal (V MIC1) and a negative power supply terminal; and a control and processing circuit comprising: a first audio input channel configured to receive the first microphone signal, a second audio input channel configured for receipt of an audio signal, a signal processor for receipt and processing of the first microphone signal and the audio signal according to a hearing loss of the user, a power supply configured to provide a first microphone supply voltage for the first microphone (M 1), a first controllable switch (SW 1) comprising a first switch control terminal, the first controllable switch (SW 1) configured to selectively connect the first microphone supply voltage to, and disconnect the first microphone supply voltage from, the first microphone (M 1) in accordance with a first switch control signal (Φ 1), and a first output port configured to provide the first switch control signal (Φ 1) to the first switch control terminal, characterized in that the signal processor is configured to set a logic state of the first output port based on at least one processing parameter used to process the first microphone signal. a first audio input channel configured to receive the first microphone signal, a second audio input channel configured for receipt of an audio signal, a signal processor for receipt and processing of the first microphone signal and the audio signal according to a hearing loss of the user, a power supply configured to provide a first microphone supply voltage for the first microphone (M 1), a first controllable switch (SW 1) comprising a first switch control terminal, the first controllable switch (SW 1) configured to selectively connect the first microphone supply voltage to, and disconnect the first microphone supply voltage from, the first microphone (M 1) in accordance with a first switch control signal (Φ 1), and a first output port configured to provide the first switch control signal (Φ 1) to the first switch control terminal, characterized in that the signal processor is configured to set a logic state of the first output port based on at least one processing parameter used to process the first microphone signal.