  Underlying mechanisms of speech perception masked by background speakers, a
common daily listening condition, are often investigated using various and
lengthy psychophysical tests. The presence of a social agent, such as an
interactive humanoid NAO robot, may help maintain engagement and attention.
However, such robots potentially have limited sound quality or processing
speed. As a first step towards the use of NAO in psychophysical testing of
speech-in-speech perception, we compared normal-hearing young adults'
performance when using the standard computer interface to that when using a NAO
robot to introduce the test and present all corresponding stimuli. Target
sentences were presented with colour and number keywords in the presence of
competing masker speech at varying target-to-masker ratios. Sentences were
produced by the same speaker, but voice differences between the target and
masker were introduced using speech synthesis methods. To assess test
performance, speech intelligibility and data collection duration were compared
between the computer and NAO setups. Human-robot interaction was assessed using
the Negative Attitude Towards Robot Scale (NARS) and quantification of
behavioural cues (backchannels). Speech intelligibility results showed
functional similarity between the computer and NAO setups. Data collection
durations were longer when using NAO. NARS results showed participants had a
more positive attitude toward robots prior to their interaction with NAO. The
presence of more positive backchannels when using NAO suggest higher engagement
with the robot in comparison to the computer. Overall, the study presents the
potential of the NAO for presentingspeech materials and collecting
psychophysical measurements for speech-in-speech perception.
