Vertical Stereophonic Localisation in the Presence of Interchannel Crosstalk: the Analysis of Frequency- Dependent Localisation Thresholds

摘要

Listening tests were conducted in order to investigate the frequency dependency of localizationudthresholds in relation to vertical interchannel crosstalk. Octave band and broadband pinkudnoise stimuli were presented to subjects as phantom images from vertically arranged stereophonicudloudspeakers located directly in front of the listening position. With respect to theudlistening position the lower loudspeaker was not elevated; the upper loudspeaker was elevatedudby 30◦. Subjects completed a method of adjustment task in which they were required to reduceudthe amplitude of the upper loudspeaker until the resultant phantom image matched the positionudof the same stimulus presented from the lower loudspeaker alone. The upper loudspeaker wasuddelayedwith respect to the lower by 0, 0.5, 1, 5, and 10 ms. The experimental data demonstratedudthat the main effect of frequency on the localization threshold was significant, with the lowudfrequency stimuli (125 and 250 Hz) requiring significantly less level reduction (less than 6 dB)udthan the mid-high (1, 2, and 8 kHz) frequency stimuli (9–10.5 dB reduction). The main effectudof interchannel time difference (ICTD) on the localization thresholds for each octave band wasudfound to be non-significant. For all stimuli interchannel level difference (ICLD) was alwaysudnecessary, indicating that the precedence effect is not a feature of median plane localization.