In a method for determining the state of a road during driving of a motor vehicle,
the sound which is generated when a vehicle tire rolls on an underlying surface
is sensed. A frequency signal is determined by means of a sound level signal which
describes the sound, and is divided into at least two sub-zones by means of at
least one limiting frequency. The sub-zones are each assigned to an associated
frequency band, and an intensity value is determined for each of at least two frequency
bands from the assigned sub-zone of the frequency signal. The intensity value is
characteristic of the sound intensity which is present in a frequency band. An
intensity ratio is formed from two intensity values by dividing the first intensity
value of the first frequency band by the second intensity value of the second frequency
band, and is used to determine the state of a road.