Regarding your question: you are right when you write to say that everything about us, tables, chairs, bricks etc. is originally emanating from sound vibration. This is also admitted in the Christian Bible wherein it is said that God said, Let there be creation. And there was creation. So, "said" means it was sound vibration; but this sound vibration is not material sound vibration because before creation of material sky and sound, transcendental sound was there. So actually the transcendental sound is the cause of creation, but material sound is not transcendental sound. We have to receive transcendental sound through the transcendental channel, therefore, Vedas are called Sruti. That means transcendental sound can be received through the ear. And by hearing this transcendental sound through the ear our heart becomes spiritually purified, and we can realize at that stage the transcendental Name, transcendental Qualities, transcendental Form, transcendental Pastimes etc. That is the way of descending process.
Because everything manifested is creation of the original transcendental Sound, therefore, factually everything is spiritual. But being covered by material cloud, we do not appreciate properly the spiritual nature of everything. The Krishna Consciousness Movement means gradually advancing towards that stage of spiritual realization. As such, the philosophy of acintya bhedabheda tattva is perfect. Everything is simultaneously one and different from the Supreme. One in quality because the original source is the Spiritual Whole, and different in quantity. This quantitative difference becomes more and more separate by increase of material consciousness.
The next question: the body of a pure devotee is all spiritual and He is not different from His body. That is also a fact. The bodies of all living entities, even though they are not pure devotees, are not actually the bodies of the spirit soul. It is always separate from the spiritual body. The Vedic mantra confirm it by the sound vibration that this spirit soul is always nonattached with the material body. Therefore, we do not see the actual spiritual body of a pure devotee; but what we see, that is matter.