Abstract:
Virtual three-dimensional (3D) auditory displays utilize signal-processing techniques to
alter sounds presented through headphones so that they seem to originate from specific
spatial locations around the listener. In some circumstances bone-conduction headsets
(bonephones) can provide an alternative sound presentation mechanism. However,
existing 3D audio rendering algorithms need to be adjusted to use bonephones rather than
headphones. This study provided anchor points for a function of shift values that could be
used to adapt virtual 3D auditory displays for use with bonephones. The shift values were
established by having participants adjust phase and amplitude of two waves in order to
cancel out the signal and thus produce silence. These adjustments occurred in a listening
environment consisting of air-conducted and bone-conducted tones, as well as air-
conducted masking. Performance in the calibration condition suggested that participants
understood the task, and could do this task with reasonable accuracy. In the bone-to-air
listening conditions, the data produced a clear set of anchor points for an amplitude shift
function. The data did not reveal, however, anchor points for a phase shift function the
data for phase were highly variable and inconsistent. Application of shifts, as well as
future research to establish full functions and better understand phase are discussed, in
addition to validation and follow-up studies.