ke punas te varṇā ye 'naiḥ pratipattṛbhir gṛhyante, narāś ca teṣām eva ye prapattāraḥ, teṣāṃ vijñānaṃ tatra yogyāviti samāsaḥ
The compound means "fit for the cognition of those [sounds and persons]" - which sounds? [Those] that are grasped by other perceivers; and the persons [are] those who are the perceivers of those [sounds].