Investigation into Vertical Stereophonic Localisation in the Presence of Interchannel Crosstalk

Listening tests were carried out on 12 subjects, using stereophonic loudspeakers arranged vertically in the median plane, to determine the threshold at which the amplitude of a delayed upper loudspeaker had to be reduced in order for stimuli to be fully localised at a lower loudspeaker. The test stimuli used were seven octave bands of noise (125, 250, 500, 1000, 2000, 4000 and 8000Hz) and one broadband source (125 - 8000Hz). The effect of frequency on the threshold was found to be significant (with the 1000 and 2000Hz bands having the lowest thresholds) whilst the effect of delay time was non-significant. The threshold for the broadband stimulus was found to be significantly lower compared to each of the noise bands.