Cargando…

Evaluation of a cochlear-implant processing strategy incorporating phantom stimulation and asymmetric pulses

OBJECTIVE: To evaluate a speech-processing strategy in which the lowest frequency channel is conveyed using an asymmetric pulse shape and “phantom stimulation”, where current is injected into one intra-cochlear electrode and where the return current is shared between an intra-cochlear and an extra-c...

Descripción completa

Detalles Bibliográficos
Autores principales: Carlyon, Robert P., Monstrey, Jolijn, Deeks, John M., Macherey, Olivier
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Informa Healthcare 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4266076/
https://www.ncbi.nlm.nih.gov/pubmed/25358027
http://dx.doi.org/10.3109/14992027.2014.932024
Descripción
Sumario:OBJECTIVE: To evaluate a speech-processing strategy in which the lowest frequency channel is conveyed using an asymmetric pulse shape and “phantom stimulation”, where current is injected into one intra-cochlear electrode and where the return current is shared between an intra-cochlear and an extra-cochlear electrode. This strategy is expected to provide more selective excitation of the cochlear apex, compared to a standard strategy where the lowest-frequency channel is conveyed by symmetric pulses in monopolar mode. In both strategies all other channels were conveyed by monopolar stimulation. DESIGN: Within-subjects comparison between the two strategies. Four experiments: (1) discrimination between the strategies, controlling for loudness differences, (2) consonant identification, (3) recognition of lowpass-filtered sentences in quiet, (4) sentence recognition in the presence of a competing speaker. STUDY SAMPLE: Eight users of the Advanced Bionics CII/Hi-Res 90k cochlear implant. RESULTS: Listeners could easily discriminate between the two strategies but no consistent differences in performance were observed. CONCLUSIONS: The proposed method does not improve speech perception, at least in the short term.