यः श्रोत्रे तिष्ठञ्छ्रोत्रादन्तरो यं श्रोत्रं न वेद यस्य श्रोत्रं शरीरं यः श्रोत्रमन्तरो यमयत्येष त आत्मान्तर्याम्यमृतः ॥३,७.१९ ॥
In plain words
He who dwells in the ear, yet is within the ear, whom the ear does not know, whose body the ear is, who from within controls the ear — he is thy Self, the inner controller, the immortal.