Breathing—the mechanical process of moving air in and out of the lungs—plays an important role in both speech and voice production; however, the emphasis placed on breathing exercises relative to voice disorders in the published literature is mixed. A review of voice therapy techniques by Casper and Murray (2000) did not suggest any breathing exercises for voice disorders. Some books on voice and voice disorders have no discussion of changing breathing behavior relative to voice disorders (Case, 1984; Colton and Casper, 1996), others do (e.g., Aronson, 1980; Boone and McFarlane, 2000; Cooper, 1973; Stemple, Glaze, and Gerdeman, 1995). Although breathing exercises are advocated by some, little is known about the role played by breathing, either directly or indirectly, in disorders of the voice. Reed (1980) noted the lack of empirical evidence that breathing exercises were useful in ameliorating voice disorders.

At present, then, there is a paucity of data on the relationship of breathing to voice disorders. The data that do exist generally describe the breathing patterns that accompany voice disorders, but there are no data on what kind of breathing behavior might contribute to voice disorders. For example, Sapienza, Stathopoulos, and Brown (1997) studied breathing kinematics during reading in ten women with vocal fold nodules. They found that the women used more air per syllable, more lung volume per phrase, and initiated breath groups at higher lung volumes than women without vocal nodules. However, as the authors point out, the breathing behavior observed in the women with nodules was most likely in response to inefficient valving at the larynx and did not cause the nodules.