The Relative Intelligibility of Male and Female Speakers: in Search of a Method

A number of professions in the service industries like telephonist, receptionist or announcer at the railway station can be observed to be typically occupied by women. Intelligibility is of crucial importance in these professions. The main task of people in the service industries is to inform the public and sometimes there is a lot of noise which troubles the messages. Are women preferred in these professions because their voices can better resist several types of noise? Do women use a more exact pronunciation? Or is the reason a more psychologically or culturally determined one? Perhaps these professions are indeed feminine, not because of the demand for intelligibility but because of the lack of status connected to them. On the other hand female voices are often excluded from applications in the speech technology because of inadequate methods for speech analysis of female voices. Most systems on speech synthesis and speech analysis are evaluated without having taken into account any female voices. In view of these phenomena we wanted to find out whether or not (fe)male speakers are more intelligible. Furthermore, from a phonetic point of view it would also be interesting to point out the voice characteristics that are influential or responsible with regard to the relative intelligibility of male and female voices. In this paper I will first describe the acoustical and perceptual differences between male and female voices and the possible role these characteristics play in determining the intelligibility. Secondly, several methods for measuring the intelligibility are discussed in order to choose a suitable test method for our purpose. Finally, the experimental procedure that has been used is described. The experiment is still in progress at the moment of writing this paper. Consequently no results can be given; they will be published in a subsequent paper.