Investigations were carried out on 10 healthy volunteers. The subjective and objective--with spirometry--airway flow was evaluated under normal conditions and after artificial narrowing of the respiratory tract. For contraction--8 pipes were used with surface section of 78.5 to 12.56 sq mm placed between mouthpiece of the device and the examined. The investigations were carried out in repose. The intensified and free flow was examined. In case of obturation of the respiratory tract characteristic changes are being observed earlier in objective than in the subjective evaluation of the patient. The changes concern the flattening of the volume flow curve and lowering of flow parameters (in sequences: PIF, PEF, FIV1, and FEV1). After application of large contractions, quotient FEV1max./FEV1free and FIV1max./FIV1free dropped several times 2 to 3. In respiration through large narrowing greater discomfort was observed in free flow than in the intensified one.