gita su-gita kartavya
kim anyaih sastra-vistaraih
ya svayam padmanabhasya
"Gita should be rightly read, with one-pointed devotion for the satisfaction of Sri Krsna. No other scripture is needed if one takes shelter of the Gita. Gita emerges from the Holy Lips of Sri Krsna and is one with Him."
It is not material sound. In material sound, you will find the thing referred to by a sound is different from the sound. If you utter the word "water, water, water," the water-word is not the water- thing. The word "water" refers to a thing understood to be water. Here you will find a difference between the water-word and the thing referred to by the word "water." But Krsna and the Name of Krsna are One and the same. Gita and Krsna are identical. So, by taking shelter of the Gita we can have contact with Krsna. We have gone through the Gita, we have read the Gita, but we have no devotion to Krsna, This is not actual reading. If we read Gita actually, we will have devotion to Sri Krsna.
His Divine Grace Srila Bhakti Ballabh Tirtha Goswami Maharaj