OBJECTIVE The aim of the present study was to clarify, by means of transcranial colour-coded duplex sonography of the basilar artery, whether there are changes in basilar artery blood flow in patients with acute inner ear disturbances and whether the flow in the basilar artery is affected by acoustic stimuli in such patients and in normal, healthy controls. METHODS Basilar artery blood flow velocity was measured in 52 patients with severe inner ear impairment over a period of two weeks by means of conventional transcranial Doppler sonography and transcranial colour-coded duplex sonography. The same measurements were carried out in 45 healthy control subjects. At the end of the two week period, both patients and controls were exposed to 70-dB noise, with basilar artery flow evaluated before and during exposure. The basilar artery Doppler curves were analysed for systolic flow velocity, end-diastolic flow velocity, resistance index (Pourcelot) and pulsatility index (Gosling). RESULTS During the first two days of the study, the basilar artery resistance index and pulsatility index were significantly (p < 0.001) higher in patients than in controls. During noise exposure, both patients and controls showed significant (p < 0.01) increases in these indices. CONCLUSIONS This study shows that temporary increases in the basilar artery resistance index and pulsatility index are found both in the acute phase of inner ear disease and during exposure to noise.