While speech pathologists and scholars of phonetics recognize four registers, vocal pedagogists are divided. Indiscriminate use of the word register has led to confusion and controversy about the number of registers in the human voice within vocal pedagogical circles. This controversy does not exist within speech pathology and the other sciences, because vocal registers are viewed from a purely physiological standpoint concerned with laryngeal function. Writers concerned with the art of singing state that there are anywhere from one to seven registers present. The diversity of opinion is wide with no consensus.