In the second part of the test, participants listened to the
original and the watermarked audio sequences in pairs and
were asked to report dissimilarities between the two signals,
using a 5-point impairment scale: (5: imperceptible, 4:
perceptible but not annoying, 3: slightly annoying, 2:annoying
1: very annoying). Table 1 presents results of the subjective
quality test, with the lowest and the highest value from the
impairment scale and, range of MOS values for particular
audio sequence during experiments and average MOS value
for given audio excerpt.