Weighting of binaural cues in the presence or absence of a reflection
Bernhard U Seeber


More than 100 years ago Lord Rayleigh postulated the Duplex Theory of auditory 
localisation according to which low frequency sounds are localised based on 
interaural time differences (ITDs), while high frequency sounds are localised 
by interaural level differences (ILDs). Later it was shown that ITDs also 
provide the main information for localisation of most wide-band sounds. Hearing 
devices may alter binaural cues and it is important to know which cues need to 
be correctly reproduced in a particular listening situation to afford the full 
benefit from binaural hearing.
In the first part binaural cue dominance is evaluated for a variety of natural 
sounds. Results confirm a relatively high weighting for ITDs, and even for a 
2 kHz high-pass noise ITDs received almost equal weight to ILDs. 
In the second part binaural cue weighting is studied in situations of the 
precedence effect. Previous studies showed a dominance of ITDs extracted from 
distinct onsets while carrier ITDs contribute for longer duration stimuli. 
However, most studies used clicks or low-pass sounds where ILDs are minimal. 
The present study thus uses natural wide-band sounds like a word or a flute 
tone to assess if the presence of a reflection changes the weighting of 
binaural cues.