1. An apparatus for determining whether a query signal and a search signal are similar to each other or not, said apparatus comprising: means for generating a signal characteristic of a first type of said query signal; means for generating a signal characteristic of a second type of said query signal; means for determining weighting values for elements of said signal characteristic of the first type, which are used in determining the distance between a signal characteristic of a first type of said search signal and the signal characteristic of the first type of said query signal, depending on said second type; means for calculating the distance between the signal characteristic of the first type of said search signal and the signal characteristic of the first type of said query signal, based on the determined weighting values; means for calculating the distance between a signal characteristic of a second type of said search signal and the signal characteristic of the second type of said query signal; and means for determining a similarity between said search signal and said query signal based on the calculated distances.