sonority

noun

1. (countable, uncountable)The property of being sonorous.

   “Another quality that bothers me is Brendel's inconsistent sonority. The treble is hard and pingy; the midrange is weighed down with a booming bass.”

2. (countable, uncountable)Relative loudness (of a speech sound); degree of being sonorous.

   “It can be seen that vowels have the highest sonority of all phonemes in English, with low vowels being even more sonorous than high vowels.”