The Influence of Azimuth on Speech Signals

The aim of the investigation was to study how speech signals are influenced by the angle of incidence of the sound towards the head, i.e. azimuth. The study was made by means of an artificial head with condenser microphones at the site of the eardrums. Speech signals were recorded via these microphones and were then subjected to spectrographic analysis. PB lists of Swedish monosyllables were also recorded via the head and their intelligibility was investigated. It was shown that azimuth has a substantial influence on speech signals. The intelligibility for binaural listening is significantly better than for monaural listening at all azimuths tested. The information reaching the ear turned towards the sound source is markedly better than at the ear turned away from the sound source.