Optimization of a Blind Speech Watermarking Technique against Amplitude Scaling

Table 3

MOS grades [23].

MOS	Quality	Quality scale	Effort required to understand meaning scale
	Excellent	Imperceptible	No effort required
	Good	Perceptible, but not annoying	No appreciable effort required
	Fair	Slightly annoying	Moderate effort required
	Poor	Annoying	Considerable effort required
	Bad	Very annoying	No meaning was understood