kṣayivegitvasampada iti / kṣayitvasampado vegitvasampado yujyanta iti vibhaktivipariṇāmena sambandhaḥ /
[The compound] "kṣayivegitvasampada" [means that it] has the properties of waning and velocity. The construction through case modification is that both the property of waning and the property of velocity are applicable [to sound].