What does the ability to suppress a single reflection tell us about 
localisation performance in rooms?

Stefan Kerber and Bernhard U. Seeber
MRC Institute of Hearing Research, University Park, Nottingham, NG7 2RD

Localisation in rooms is characterised by the presence of multiple reflections 
interfering with the direct sound from source to listener. Nevertheless, due to 
the “precedence effect”, normal hearing listeners are able to cope in such 
situations by apparently ignoring the later arriving reflections. Most studies 
on the precedence effect have used a paradigm in which a sound (the “lead”) and 
a single delayed reflection (the “lag”) are played from different directions. 
In realistic situations, however, multiple early reflections as well as late 
reflections might interfere with the direct sound. The aim of the current study 
is to compare to what degree localisation performance in rooms can be predicted 
from the simple lead-lag precedence effect paradigm. Participants localised 
lead-lag stimuli for different relative levels and delays of the lag to quantify 
how listeners cope with differently pronounced single reflections. Additionally, 
localisation was assessed in simulated rooms for various direct-to-reverberant 
ratios, demonstrating a decline in localisation performance for smaller ratios. 
The comparison of the ability to cope with single reflections and with simulated 
reverberation of rooms will show to what degree the former can be used to 
predict the latter.