Pitch-matched electrode pairs do not maximize binaural time-difference sensitivity

Evidence

The matched electrodes are R4.4 (pitch comparison), R6-R8 (best IPTD performance), and R6 (largest BIC amplitude). In contrast to the common assumption that pitch-matched pairs maximize sensitivity to binaural cues, for this subject the pairs with best IPTD sensitivity are 1.6–3.6 electrodes away from (interpolated) electrode identical pitch perception. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1469

Interaural pitch comparison shows some predictive value in selecting interaural electrode pairs, but it may not fully compensate for any underlying differences between the two implanted cochleae. In line with previous studies (van Hoesel and Clark 1997 ; Long et al. 2003 ; Poon et al. 2009 ) the pitch matched pair does not guarantee best IPTD sensitivity. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1471

(1) Pairwise pitch comparison results highly depend on the participant’s clinical frequency-place fitting map. The matched pair indicates a similar frequency range in the map, except for one subject which was implanted only 9 months before the experiment. (2) Both BIC and IPTD based pairing results indicate a large 2–3 electrode mismatch for some subjects. There is clear correlation between the mismatches indicated by these two methods. (3) In line with Poon et al. ( 2009 ) there is no correlation between the pitch matched pairs and the IPTD matched pair and in line with He et al. ( 2012 ) there is no correlation between the pitch matched pairs and the BIC matched pair. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1451

Categorization

• XREF: Connects to peripheral-place and tonotopic-mapping literature in cochlear implant psychophysics — pitch and timing are coded by overlapping but distinct mechanisms. — connects to: Interaural place-of-stimulation mismatch shrinks the binaural interaction component’s magnitude. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1448; Binaural cue methods agree on electrode mismatch while pitch matching does not; BIC amplitude does not correlate with interaural pitch comparison outcomes. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1452 (+3 more)
• corroborated: 8 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 1469; Dijk, Pim van, Physiology, Psychoacoustics and…, 1471; Dijk, Pim van, Physiology, Psychoacoustics and…, 1451

Broader Connections

• Binaural cue methods agree on electrode mismatch while pitch matching does not #corroborates (0.85)
• BIC amplitude does not correlate with interaural pitch comparison outcomes. #corroborates (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1452