title: Combined electric and acoustic hearing performance with Zebra® speech processor: speech reception, place, and temporal coding evaluation.
abstract: OBJECTIVE
  To assess the auditory performance of Digisonic(®) cochlear implant users with electric stimulation (ES) and electro-acoustic stimulation (EAS) with special attention to the processing of low-frequency temporal fine structure.
  
  
  METHODS
  Six patients implanted with a Digisonic(®) SP implant and showing low-frequency residual hearing were fitted with the Zebra(®) speech processor providing both electric and acoustic stimulation. Assessment consisted of monosyllabic speech identification tests in quiet and in noise at different presentation levels, and a pitch discrimination task using harmonic and disharmonic intonating complex sounds ( Vaerenberg et al., 2011 ). These tests investigate place and time coding through pitch discrimination. All tasks were performed with ES only and with EAS.
  
  
  RESULTS
  Speech results in noise showed significant improvement with EAS when compared to ES. Whereas EAS did not yield better results in the harmonic intonation test, the improvements in the disharmonic intonation test were remarkable, suggesting better coding of pitch cues requiring phase locking.
  
  
  CONCLUSIONS
  These results suggest that patients with residual hearing in the low-frequency range still have good phase-locking capacities, allowing them to process fine temporal information. ES relies mainly on place coding but provides poor low-frequency temporal coding, whereas EAS also provides temporal coding in the low-frequency range. Patients with residual phase-locking capacities can make use of these cues.
authors: Bart
authors: B
authors: Vaerenberg
authors: Vincent
authors: V
authors: Péan
authors: Guillaume
authors: G
authors: Lesbros
authors: Geert
authors: G
authors: De Ceulaer
authors: Karen
authors: K
authors: Schauwers
authors: Kristin
authors: K
authors: Daemers
authors: Dan
authors: D
authors: Gnansia
authors: Paul J
authors: PJ
authors: Govaerts
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001303:Auditory Cortex / Q000502:physiology; D001309:Auditory Threshold; D002648:Child; D019929:Cochlear Implantation; D003054:Cochlear Implants; D006320:Hearing Tests; D006801:Humans; D008875:Middle Aged; D009622:Noise; D010897:Pitch Discrimination; D059629:Signal-To-Noise Ratio; D065855:Spatial Processing; D013067:Speech Perception; D013069:Speech Reception Threshold Test; D055815:Young Adult
keywords: A§E; Cochlear implant; Disharmonic intonation; EAS; Electro-acoustic stimulation; Harmonic intonation; Pitch; Residual hearing; TFS; Temporal fine structure