Method for generating an audio signal for the acoustic rendering, to the user of a portable metal detection apparatus, using at least one electroacoustic transducer, of an electromagnetic target detection signal the amplitude of which may vary with a determined dynamic range, the method comprising the following steps: - reducing the dynamic range of the detection signal so that it corresponds to a desired dynamic range of the audio signal; and - generating (27, 28) the audio signal on the basis of the detection signal with the reduced dynamic range, wherein: - reducing the dynamic range of the detection signal comprises: - - clipping the detection signal on the basis of a determined detection threshold; clipping the detection signal comprising clipping said signal below the detection threshold; - - applying, to the clipped detection signal, an overall determined dynamic range compression rate, which depends on the ratio between the dynamic range of the detection signal and the desired dynamic range of the audio signal; and - - shifting the compressed detection signal so as to set a desired minimum level of the audio signal; and characterized in that: the overall determined dynamic range compression rate is strictly between 0 and 1; and - applying the overall dynamic range compression rate to the clipped detection signal comprises segmenting the dynamic range of the detection signal into a plurality of separate portions (Z1, Z2, Z3), and also applying respective local dynamic range modification rates to different portions of the clipped detection signal. - reducing the dynamic range of the detection signal so that it corresponds to a desired dynamic range of the audio signal; and - generating (27, 28) the audio signal on the basis of the detection signal with the reduced dynamic range, - reducing the dynamic range of the detection signal comprises: - - clipping the detection signal on the basis of a determined detection threshold; clipping the detection signal comprising clipping said signal below the detection threshold; - - applying, to the clipped detection signal, an overall determined dynamic range compression rate, which depends on the ratio between the dynamic range of the detection signal and the desired dynamic range of the audio signal; and - - shifting the compressed detection signal so as to set a desired minimum level of the audio signal; and - - clipping the detection signal on the basis of a determined detection threshold; clipping the detection signal comprising clipping said signal below the detection threshold; - - applying, to the clipped detection signal, an overall determined dynamic range compression rate, which depends on the ratio between the dynamic range of the detection signal and the desired dynamic range of the audio signal; and - - shifting the compressed detection signal so as to set a desired minimum level of the audio signal; and - applying the overall dynamic range compression rate to the clipped detection signal comprises segmenting the dynamic range of the detection signal into a plurality of separate portions (Z1, Z2, Z3), and also applying respective local dynamic range modification rates to different portions of the clipped detection signal.