No inanimate thing moves on its own. In order for anything to move in and of itself it would have to be alive; "endowed with life or spirit".

Now think about this in the context of this chapter. The word, a word spoken, a word heard is, has to be alive. A sound is alive. It has substance, it has life, it is spirit, it is living, it is filled with life. It is not an inanimate object, it does not just happen to vibrate in and of itself, it is a living, vibrating organism! That is why it vibrates; we can say that no external source or substance is acting upon it to make it vibrate.

A vibration causes a sound, which, when articulated, brings a word. A word is made of the substance of sound. The sound has life. A word carries with it all that man is made of and/or expressing. Man creates the sound and imparts to it the substance of who he is. his life. That substance is then communicate to all those who are hearing that man.

God made us in His image and as such He is the originator of this substance. Man's word, man's sound is full of his substance, his life. In the same way God's Word, His sound, is full of His substance. When God speaks He creates a sound which when heard is imparted to the hearer. It is this life substance that is communicated and transmitted by God to us.

You hear yourself read to yourself, don't you? You can hear yourself think, right? There is no action of the vocal chords or on the physical ear involved in that, is there? No, it is the spirit using your soul to speak internally. That is what you hear. Your thoughts, your purposes, those are ever flowing in and through your heart, that is where you hear yourself speak from with your spirit.

Now, I don't want to get off track here but it is imperative that you understand this is how you are made. This will help make what I'm saying quite a bit clearer.

The heart is that place in man where thoughts reside, decisions are pondered and made. I like to think of it as the "middle of man", residing in the center of the soul which allows for the contemplation of all the things concerning man, spirit, soul and body. The heart in essence is the "decision maker". It sits between and conjoins the spirit and soul. It is open to everything that is happening both inside and outside. From the spirit and soul and body, all is open to the heart of man.

Let's look at the Hebrew and Greek definition of the word "heart".

the heart; also used (figuratively) very widely for the feelings, the will and even the intellect; likewise for the center of anything.

"the heart" (Eng., "cardiac," etc.), the chief organ of physical life ("for the life of the flesh is in the blood," Lev_17:11), occupies the most important place in the human system. By an easy transition the word came to stand for man's entire mental and moral activity, both the rational and the emotional elements. In other words, the heart is used figuratively for the hidden springs of the personal life. "The Bible describes human depravity as in the 'heart,' because sin is a principle which has its seat in the center of man's inward life, and then 'defiles' the whole circuit of his action, Mat_15:19, Mat_15:20.

On the other hand, Scripture regards the heart as the sphere of Divine influence, Rom_2:15; Act_15:9.... The heart, as lying deep within, contains 'the hidden man,' 1Pe_3:4, the real man. It represents the true character but conceals it" (J. Laidlaw, in Hastings' Bible Dictionary.).