The senses cannot themselves apprehend their respective forms. The Soul is omniscient. It sees all things. Being omniscient, it is the Soul that sees the senses.
श्रोत्रादीनि च पश्यन्ति स्वं स्वमात्मानमात्मना। सर्वज्ञः सर्वदर्शी च सर्वज्ञस्तानि पश्यति॥