scholarly journals The effect of phantom stimulation and pseudomonophasic pulse shapes on pitch perception by cochlear implant listeners

2020 ◽  
Author(s):  
Wiebke Lamping ◽  
John M. Deeks ◽  
Jeremy Marozeau ◽  
Robert P. Carlyon
Keyword(s):  
Cochlear Implants ◽  
Pitch Perception ◽  
Electrode Pair ◽  
Bipolar Electrode ◽  
Clinical Settings ◽  
Temporal Acuity ◽  
Discrimination Procedure ◽  
High Pulse ◽  
Neural Excitation ◽  
Rate Discrimination

It has been suggested that a specialised high-temporal-acuity brainstem pathway can be activated by stimulating more apically in the cochlea than is achieved by cochlear implants (CIs) when programmed with contemporary clinical settings. Muliple experiments were carried out to test the effect of phantom stimulation and asymmetric current pulses, both supposedly stimulating beyond the most apical electrode of a CI, on pitch perception. The two stimulus types were generated using a bipolar electrode pair, composed of the most apical electrode of the array and a neighbouring, more basal electrode. Experiment 1 used a pitch-ranking procedure where neural excitation was shifted apically or basally using so-called phantom stimulation. No benefit of apical stimulation was found on the highest rate up to which pitch ranks increased, nor on the slopes of the pitch-ranking function above 300 pulses per second (pps). Experiment 2 used the same procedure to study the effects of asymmetric pseudomonophasic pulses, where the locus of excitation was manipulated by changing stimulus polarity. A benefit of apical stimulation was obtained only for the slopes above 300 pps. Experiment 3 used an adaptive rate discrimination procedure and a small but significant benefit of apical stimulation was found. Overall the results show some benefit for apical stimulation on temporal pitch processing at high pulse rates but reveal that the effect is rather small and highly variable across listeners. The results also provide some indication that the benefit of apical stimulation may decline over time since implantation.

scholarly journals The Effect of Phantom Stimulation and Pseudomonophasic Pulse Shapes on Pitch Perception by Cochlear Implant Listeners

2020 ◽  
Vol 21 (6) ◽  
pp. 511-526
Author(s):  
Wiebke Lamping ◽  
John M. Deeks ◽  
Jeremy Marozeau ◽  
Robert P. Carlyon
Keyword(s):  
Cochlear Implants ◽  
Pitch Perception ◽  
Electrode Pair ◽  
Bipolar Electrode ◽  
Clinical Settings ◽  
Temporal Acuity ◽  
Discrimination Procedure ◽  
High Pulse ◽  
Neural Excitation ◽  
Rate Discrimination

Abstract It has been suggested that a specialized high-temporal-acuity brainstem pathway can be activated by stimulating more apically in the cochlea than is achieved by cochlear implants (CIs) when programmed with contemporary clinical settings. We performed multiple experiments to test the effect on pitch perception of phantom stimulation and asymmetric current pulses, both supposedly stimulating beyond the most apical electrode of a CI. The two stimulus types were generated using a bipolar electrode pair, composed of the most apical electrode of the array and a neighboring, more basal electrode. Experiment 1 used a pitch-ranking procedure where neural excitation was shifted apically or basally using so-called phantom stimulation. No benefit of apical phantom stimulation was found on the highest rate up to which pitch ranks increased (upper limit), nor on the slopes of the pitch-ranking function above 300 pulses per second (pps). Experiment 2 used the same procedure to study the effects of apical pseudomonophasic pulses, where the locus of excitation was manipulated by changing stimulus polarity. A benefit of apical stimulation was obtained for the slopes above 300 pps. Experiment 3 used an adaptive rate discrimination procedure and found a small but significant benefit of both types of apical stimulation. Overall, the results show some benefit for apical stimulation on temporal pitch processing at high pulse rates but reveal that the effect is smaller and more variable across listeners than suggested by previous research. The results also provide some indication that the benefit of apical stimulation may decline over time since implantation.

Music Training Improves Pitch Perception in Prelingually Deafened Children With Cochlear Implants

PEDIATRICS ◽  
2010 ◽  
Vol 125 (4) ◽  
pp. e793-e800 ◽  
Author(s):  
J. K.-C. Chen ◽  
A. Y. C. Chuang ◽  
C. McMahon ◽  
J.-C. Hsieh ◽  
T.-H. Tung ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Pitch Perception ◽  
Music Training

Abstract 19778: Novel Strategy for Improved Substrate Mapping of the Atria: Omnipolar Catheter and Signal Processing Technology Assesses Electrogram Signals Along Physiologic and Anatomic Directions

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
D Curtis Deno ◽  
Ram Balachandran ◽  
Dennis Morgan ◽  
Stéphane Massé ◽  
Kumaraswamy Nanthakumar
Keyword(s):  
Signal Amplitude ◽  
Orientation Dependence ◽  
Electrode Pair ◽  
Bipolar Electrode ◽  
Bipolar Electrodes ◽  
Surface Normal ◽  
3D Mapping System ◽  
Potential Strategy ◽  
Novel Strategy ◽  
Definition Of

Introduction: Substrate mapping is evolving as a potential strategy for atrial fibrillation ablation. Defining scar borders and functional boundaries is typically under taken with bipolar electrodes. Catheter orientation affects electrogram (EGM) signal amplitude due to an orientation dependence of bipoles. We developed orientation independent Omnipolar Technology (OT) and compared OT EGM amplitude with traditional bipolar (Bi) methods. Methods: Four anesthetized swine were studied in 6 sessions with a 3D mapping system and a multielectrode OT ablation catheter placed in RA and LA locations in 4 rhythms. With the OT catheter in a stable location, 30 successive atrial beats were acquired. OT electrodes provided bipole (Bi) as well as OT signals along both activation (OTa) and surface normal (OTn) directions. Peak to peak amplitudes (Vpp) of OT and Bi signals were compared for magnitude and consistency. Results: As shown in the table, OT signal amplitudes over all atrial locations and rhythms were greater than traditional bipole amplitudes. The coefficients of variation for signal amplitude over successive cardiac beats were substantially less for OTa and OTn (*p < 0.01 with respect to Bi) than for Bi, reflecting electrode pair orientation effects. Conclusions: Distinct electrogram signals were resolved by OT along physiologic (activation) and anatomic (surface normal) directions. Catheter orientation independent OT signal amplitudes were more self-consistent and reliable than those from orientation dependent bipolar electrode pairs. Omnipolar technology approaches may permit more accurate and specific definition of substrate and thus catheter ablation of arrhythmias.

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