Just by thinking that ambaal’s eyes extend up to the ears, the power of sound is so much that the diseases of both the eyes and ears are cured! Here it appears there is some kind of correlation between the effects of sound and the meanings of the words which make the sound.
In another shloka (#58), though both these (eyes and ears) are mentioned, the effect is said to be ‘cure of all diseases’. What is the logic behind this? You cannot answer the question. We have only to say ‘Sound value is such’!