The device executes a method for determining the delay time of a first wavelet in a transmission path (I1). For this purpose, the first wavelet is transmitted into the transmission path (I1) at a time after a reference time. After passing through the transmission path (I1), the delayed and typically deformed transmission wavelet is scalar-multiplied with a second (analysis) wavelet. The result is compared to a reference value. The scalar product value adopts the reference value at a time (ts). The delay of the first and/or second wavelet in relation to the reference time is adjusted according to said time (ts) in relation to the reference time. An amplitude adjustment is not carried out.