The assessment of tonal components in the environmental noise: features and limitations of the Italian legislation

In the Italian legislation the detection of tonal components in the environmental noise requires a preliminary test based only on subjective perception and, afterwards, 1/3 octave frequency band analysis. To take account of the increased annoyance due to these components a fixed penalty of 3 dB has to be added to the LAeq of the noise. Limitation of the procedure and indication of the improvements have been obtained by a study based on laboratory listening tests. The results have shown that the procedure does not match the subjective perception of tones, even when they are judged either clearly audible or prominent. The tonal penalty decreases of 0.7 dB for every increase of 3 dB in LAeq within the range 45 to 65 dB(A).