The device has a nebuliser (10) and a nose piece (11) for introducing an aerosol flow into a pair of two nostrils (12) of a user. A pressure fluctuation source generates pressure fluctuation. Another nose piece (14) introduces the pressure fluctuation into another pair of nostrils (15) in order to superimpose the pressure fluctuation and the aerosol flow. A sensor system with a pressure sensor (19) for detecting a signal of the pressure fluctuation that arrives at the nose piece. An evaluation unit (18) concludes the degree of closure of the velum of the user based on the signal.