2. Auditory effects of noise

2.1 Discomfort

The loudness scales that characterize the subjective intensity of perceived sounds can be obtained either by comparing a pure tone of any frequency with a 1,000 Hz tone giving the same level sensation (phone scale), or by pairwise comparison of sounds of the same frequency, one of which gives a level sensation twice that of the other (sones scale). Both forms of analysis reveal non-linearities in intensity perception in relation to the physical level of the stimulus.

It is precisely to take account of this auditory filtering effect that weighting curves have been introduced. Their role...