Department of Electrical, Electronic and Computer Engineering, University of Pretoria, Pretoria 0002, South Africa
Strydom, T., Department of Electrical, Electronic and Computer Engineering, University of Pretoria, Pretoria 0002, South Africa; Hanekom, J.J., Department of Electrical, Electronic and Computer Engineering, University of Pretoria, Pretoria 0002, South Africa
Synthesis (carrier) signals in acoustic models embody assumptions about perception of auditory electric stimulation. This study compared speech intelligibility of consonants and vowels processed through a set of nine acoustic models that used Spectral Peak (SPEAK) and Advanced Combination Encoder (ACE)-like speech processing, using synthesis signals which were representative of signals used previously in acoustic models as well as two new ones. Performance of the synthesis signals was determined in terms of correspondence with cochlear implant (CI) listener results for 12 attributes of phoneme perception (consonant and vowel recognition; F1, F2, and duration information transmission for vowels; voicing, manner, place of articulation, affrication, burst, nasality, and amplitude envelope information transmission for consonants) using four measures of performance. Modulated synthesis signals produced the best correspondence with CI consonant intelligibility, while sinusoids, narrow noise bands, and varying noise bands produced the best correspondence with CI vowel intelligibility. The signals that performed best overall (in terms of correspondence with both vowel and consonant attributes) were modulated and unmodulated noise bands of varying bandwidth that corresponded to a linearly varying excitation width of 0.4 mm at the apical to 8 mm at the basal channels. © 2011 Acoustical Society of America.
Acoustic model; Amplitude envelope; Cochlear implant listeners; Electric stimulation; Information transmission; Measures of performance; Noise bands; Spectral peak; Vowel recognition; Acoustic noise; Cochlear implants; Digital filters; Electrophysiology; Electrotherapeutics; Speech intelligibility; Speech processing; Linguistics; adolescent; adult; analysis of variance; article; auditory stimulation; auditory threshold; cochlea prosthesis; comparative study; human; prosthesis; signal processing; sound detection; speech; speech audiometry; speech intelligibility; speech perception; time; Acoustic Stimulation; Adolescent; Adult; Analysis of Variance; Audiometry, Speech; Auditory Threshold; Cochlear Implants; Humans; Prosthesis Design; Signal Processing, Computer-Assisted; Sound Spectrography; Speech Acoustics; Speech Intelligibility; Speech Perception; Time Factors; Young Adult