The influence of dummy head on measuring speech intelligibility

In order to investigate the influence of dummy head on measuring speech intelligibility, the objective and subjective speech intelligibility evaluation experiments were respectively carried out for different spatial configurations of a target source and a noise source in a horizontal plane. The differences between standard STIPA measured without a dummy head and binaural STIPA measured with a dummy head were compared and the correlation of subjective speech intelligibility and objective STIPA was analyzed. It is showed that the position of sound source affects significantly on binaural STIPA and subjective intelligibility measured by a dummy head or measured in a real-life scenario. The standard STIPA is closer to the lower value of the two binaural STIPA values. The speech intelligibility is higher for a single ear which is on the same side with the target source or on the other side of the noise source. Binaural speech intelligibility is always the lowest when both target and noise sources are at the same place but once apart the speech intelligibility will increase sharply. It is also found that the subjective intelligibility measured by a dummy head or measured in a real-life scenario is uncorrelated with standard STIPA, but correlated highly with STIPA measured with a dummy head. The subjective intelligibility of one single ear is correlated highly with STIPA measured at the same ear, and the binaural speech intelligibility is in well agreement with the higher value of the two binaural STIPA values.