AUTHOR=Fan Langchen , Henry Kenneth S. , Carney Laurel H. 

TITLE=Responses to dichotic tone-in-noise stimuli in the inferior colliculus

JOURNAL=Frontiers in Neuroscience

VOLUME=16

YEAR=2022

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2022.997656

DOI=10.3389/fnins.2022.997656

ISSN=1662-453X

ABSTRACT=<p>Human listeners are more sensitive to tones embedded in diotic noise when the tones are out-of-phase at the two ears (N<sub>0</sub>S<sub>π</sub>) than when they are in-phase (N<sub>0</sub>S<sub>0</sub>). The difference between the tone-detection thresholds for these two conditions is referred to as the binaural masking level difference (BMLD) and reflects a benefit of binaural processing. Detection in the N<sub>0</sub>S<sub>π</sub> condition has been explained in modeling studies by changes in interaural correlation (IAC), but this model has only been directly tested physiologically for low frequencies. Here, the IAC-based hypothesis for binaural detection was examined across a wide range of frequencies and masker levels using recordings in the awake rabbit inferior colliculus (IC). IAC-based cues were strongly correlated with neural responses to N<sub>0</sub>S<sub>π</sub> stimuli. Additionally, average rate-based thresholds were calculated for both N<sub>0</sub>S<sub>0</sub> and N<sub>0</sub>S<sub>π</sub> conditions. The rate-based neural BMLD at 500 Hz matched rabbit behavioral data, but the trend of neural BMLDs across frequency differed from that of humans.</p>