Binaural brainstem neurons compare only interaurally place-matched inputs.

Evidence

Since the inputs to the NH binaural system from the two ears can be assumed to be well matched and binaural brainstem neurons are comparing only by interaurally place matched inputs, it is very important to determine interaural electrode pairs for frequency matching the electrode arrays in the two ears to compensate for any differences in the implanted cochleae. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1453

Bilateral cochlear implantation seeks to restore the advantages of binaural hearing to the profound deaf by providing binaural cues that are important for binaural perception, such as binaural fusion, sound localization and better detection of signals in noise. Most bilateral cochlear implant (BiCI) users have shown improvements compared to their ability when only one CI was used. However, compared to normal hearing (NH) individuals, the average performance of BiCI users is still worse and has a large variability in performance amongst them … One likely reason for the worse performance of BiCI users is the interaural electrodes mismatch between two CIs because of different surgery insertion depth or different implant length. Since the inputs to the NH binaural system from the two ears can be assumed to be well matched and binaural brainstem neurons are comparing only by interaurally place matched inputs, it is very important to determine interaural electrode pairs for frequency matching the electrode arrays in the two ears to compensate for any differences in the implanted cochleae. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1453

Categorization

• XREF: Connects to the reader’s interest in binaural physiology and how the brainstem performs interaural comparisons — a mechanism-level fact about normal hearing that explains why CI electrode mismatch degrades performance. — connects to: Unequal neural survival across ears can invalidate place-matching logic for the BIC; Interaural place-of-stimulation mismatch shrinks the binaural interaction component’s magnitude. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1448; Pitch-matched electrode pairs do not maximize binaural time-difference sensitivity — Dijk, Pim van, Physiology, Psychoacoustics and…, 1469
• corroborated: 3 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 1453

Broader Connections

• Interaural place-of-stimulation mismatch shrinks the binaural interaction component’s magnitude. #complicates (0.85) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1448
• Pitch-matched electrode pairs do not maximize binaural time-difference sensitivity #complicates (0.82) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1469