The goal of voice training and "re-training" is to eliminate compensatory laryngeal behaviors (i.e., muscular tension) in the speaking and singing voice. It is no longer necessary to "blame" the voice user of improper technique, misuse or abuse. Vocal problems usually occur when there is an underlying vocal fold problem. Most professional (and even non-professional) voice users know when something is amiss with their voice.
Your vocal folds are not the "end product" of your voice. Your voice begins in your throat (sounding much like a mere "buzz") which travels up the throat and into the mouth. Consequently, your vocal "signature" resides in the mouth. Your vocal resonators (mouth, throat and nose) embellish the sound, as you use your articulators (jaw, tongue) to shape the final product. So you can have "imperfect" vocal folds and still have a formidable sound.
Vocal Intensity "Play" (VIP) is a technique comprised of voice exercises that are applicable to singers and non-singers alike. An imbalance in the vocal resonators may predispose the voice user to vocal injury or inefficiency (i.e., compensatory muscle patterns) and create and thereafter maintain a pathologic condition.
Theoretically, these exercises are based on transfers in vocal intensity. These "transfers" of intensity (soft-loud-soft)) may be helpful in treating a variety of voice disorders and help facilitate the retraining of the injured and non-injured voice. The shifts of intensity allow the vocal folds a chance to "relax" so-to-speak.
Energy is the property of vocal tone. We sometimes can identify that some tones are more intense than others (which is the opposite of a breathy tone). An intense tone is not necessarily louder, just more compressed. It may be perceived as louder because the singer is able to make filter tract adjustments while using less respiratory energy than that of a loud breathy tone.
Your breath does not carry the tone! The actual breath goes only a short way and moves rather slowly. As the air travels through the throat, compression waves are created which travel through the atmosphere at 1100 feet per second. Moral of this story: Don't' Waste the Breath! When energy is used with freedom, the maximum volume can be produced without effort.
Flexibility is key to avoiding injury. These exercises are designed to enhance vocal fold flexibility (vibration) while allowing the singer to make filter tract adjustments to increase resonance and intensity (therefore reducing tension at the vocal fold level).
This is my basic philosophy for voice retraining.