The tests related to air usage are valuable for evaluating phonatory function of clinical cases having glottic incompetence. Measurement of maxium phonation time (MPT), phonation quotient (PQ) and mean air flow rate (AFR) are important test for voice disorders. Author obtained following clinical results from 56 cases of laryngeal disorders. 1) In laryngeal disorders, unilateral laryngeal lesions were 35 cases (62.5%) and bilateral laryngeal lesions were 21 cases (37.5%). 2) Sex incidence of laryngeal lesions were 39 cases (69.8%) in male and 17 cases (30.2%) in female. 3) In maxium phonation time, below 10 seconds were 26 cases (46.4%) and above 10 seconds were 30 cases (53.6%). 4) In phonation quotient, below 300ml/sec were 33 cases (58.9%) and above 300ml/sec were 23 cases (41.1%). 5) In mean air flow ratio, below 300ml/sec were 37 cases (66.1%) and above 300ml/sec were 19 cases (33.9%). 6) Postoperative voice examinations were incomparably superior to that of preoperative cases.