Auditory processing of echoes in the cochlea and brainstem involve several nuclei that show hypertrophy and differentiation in bats compared with other mammals, including the anteroventral cochlear nucleus, superior olivary complex and the inferior colliculus [16], [17], which appears to show specialisations for echo detection [18] [20].
Scanning was performed on a 3T Trio Siemens Scanner at the MRC-CBU, Cambridge, using a fast sparse imaging protocol to minimize the interference of scanner noise with auditory processing (gradient-echo EPI sequence, TR = 3.4 s, TA = 2 s, TE = 30 ms, flip angle 78 degrees, matrix size 64 × 64, FOV = 192 × 192 mm, 32 oblique slices 3-mm thick, 0.75-mm gap).
Thomas Nagel famously argued (1974) that are unavoidable limits placed on our ability to understand the phenomenology of bat experience by our inability to empathetically take on an experiential perspective like that which characterizes the bat's echo-locatory auditory experience of its world.
The sound localization method is based on a model of the precedence effect of the human auditory system to cope with echoes and reverberations.
These results echo related findings in the auditory domain where it has been shown that changes in eye position affect auditory lateralization.
Humans acting as a proxy for dolphins are being used in a listening experiment to determine how well a mammalian auditory system can discriminated these fish echoes.
The researchers suggested that by making fainter clicks when it is close to a target, the dolphin stabilizes the loudness of the echo, making it easier for its auditory system to analyze.
Our finding that internal noise reduces with age echoes a previous study in the auditory domain which reported higher internal noise in children aged 6 11 years compared to adults (Buss et al., 2006), as well as reports of increased levels of internal noise in infants (Skoczenski and Norcia, 1998).
The auditory spatial processing was based on the "Bat-ears" echo sounds, which were novel to the participants.
In other words, the auditory stimuli were recordings of previous played sounds containing the echo cues created by obstacles at different spatial locations rather than sounds emitted from spatially distinct areas.
Our aim was to confirm the usefulness of the perilymphatic signal changes on T2-weighted (T2W) gradient-echo sequence to differentiate vestibular schwannomas from internal auditory canal (IAC) meningiomas, through a compartmental analysis of inner ear fluids signal intensity.
