  Many people with hearing loss struggle to comprehend speech in crowded
auditory scenes, even when they are using hearing aids. Future hearing
technologies which can identify the focus of a listener's auditory attention,
and selectively amplify that sound alone, could improve the experience that
this patient group has with their hearing aids. In this work, we present the
results of our experiments with an ultra-wearable in-ear electroencephalography
(EEG) monitoring device. Participants listened to two competing speakers in an
auditory attention experiment whilst their EEG was recorded. We show that
typical neural responses to the speech envelope, as well as its onsets, can be
recovered from such a device, and that the morphology of the recorded responses
is indeed modulated by selective attention to speech. Features of the attended
and ignored speech stream can also be reconstructed from the EEG recordings,
with the reconstruction quality serving as a marker of selective auditory
attention. Using the stimulus-reconstruction method, we show that with this
device auditory attention can be decoded from short segments of EEG recordings
which are of just a few seconds in duration. The results provide further
evidence that ear-EEG systems offer good prospects for wearable auditory
monitoring as well as future cognitively-steered hearing aids.
