What are the effects of voice use and training?

The amount of voice use and training also affects voices. Inquiry into vocal habits frequently reveals correctable causes for voice difficulties. Extensive untrained speaking under adverse environmental circumstances is a common example. Such conditions occur, for example, among stock traders, sales people, restaurant personnel, and people who speak over the telephone in noisy offices. The problems are aggravated by habits that impair the mechanics of voice production such as sitting with poor posture and bending the neck to hold a telephone against one shoulder. Subconscious efforts to overcome these impediments often produce enough voice abuse to cause vocal fatigue, hoarseness, and even nodules (callous-like growths, usually on both vocal folds). Recognizing and eliminating the causal factors usually results in disappearance of the nodules and improved voice.