This paper describes the development of a software based technique to obtain by measurement objective parameters to define the annoyance of engine noise. This task requires the application of advanced digital binaural measurement techniques. On the basis of noise data recorded via an artificial head system, fully digital data processing techniques and statistical evaluation methods for the subjective ranking procedures were developed and verified with numerous test personnel. This method lead to the ultimate development goal of being able to describe and assess engine noise character by a combination of objective parameters.Using such, an assessment procedure for subjective noise character, the necessary improvements can be made to achieve given target values. This is demonstrated by examples of application of the technique for the improvement of the noise character of power trains and vehicles.