Study of Quality Perception on Music in New Cochlear Implanted Subjects Using or Not a Fine Structure Strategy

Study of Quality Perception on Music in New Cochlear Implanted Subjects Using or Not a Fine Structure Strategy

Evaluation of the Impact of Coding the Fine Structure of the Sound on the Musical Perception in New Cochlear Implanted Subjects. Prospective Randomized Crossover Study.

Main objective: Show the superiority of Fine Structure (FS4) strategy compared to Continuous Interleaved Sampling (HDCIS) strategy on the qualitative preference for the listening of musical pieces. Secondary objectives Show the superiority of FS4 strategy compared to the HDCIS strategy on the perception of musical elements (contour test). Analyze the link between the results of musical perception tests and the subjective preference of musical listening. Show the non inferiority of FS4 strategy compared to the HDCIS strategy on the perception of speech elements. Analyze the link between the results of musical perception tests and the results of the perception of speech elements. Analyze the qualitative multidimensional perception with HDCIS and FS4

Introduction: At present, most people with modern cochlear implant systems can understand speech using the device alone, at least under favorable listening conditions. In recent years, research has increasing focussed on how implant users perceive sounds other than speech. In particular, music perception is of interest. A review of the literature on musical perception with traditional implants, coding only the temporal envelope [McDermott 2004], revealed the following elements: On average, implant users perceive the rhythm approximately as well as listeners with normal hearing With technically sophisticated multi-channel sound processors, melody recognition, especially without rhythmic or verbal cues, is poor. The perception of timbre, especially the sounds of musical instruments, is generally unsatisfactory. Implant users tend to rate the quality of musical sounds as less enjoyable than listeners with normal hearing And studies show that the fine structure of sound is the main vector of information for music and the location of sounds. [Smith et al. 2002] It therefore seems necessary to focus on the contribution of the coding of the fine temporal structure of sound to the cochlear implant. Main objective: Show the superiority of FS4 strategy compared to HDCIS strategy on the qualitative preference for the listening of musical pieces. Secondary objectives: Show the superiority of FS4 strategy compared to the HDCIS strategy on the perception of musical elements (contour test). Analyze the link between the results of musical perception tests and the subjective preference of musical listening. Show the non inferiority of FS4 strategy compared to the HDCIS strategy on the perception of speech elements. Analyze the link between the results of musical perception tests and the results of the perception of speech elements. Analyze the qualitative multidimensional perception with HDCIS and FS4 Plan of the study: It is a prospective open monocentric randomized crossover study: measures will be done on the patient at 15 days and 30 days post-activation.

two arms A and B: Arm A: patient's fitting with strategy FS4 --> 15 days use --> tests and patient's fitting with strategy HDCIS --> 15 days use --> tests Arm B: patient's fitting with strategy HDCIS --> 15 days use --> tests and patient's fitting with strategy FS4 --> 15 days use --> tests

cochlear implant with FineHearing strategy first during 15 days then with HDCIS strategy during 15 days

The Gabrielsson scale (1988) is used to evaluate perceived sound quality as a multidimensional phenomenon, that is composed of a number of separate perceptual dimensions. Eight perceptual dimensions are evaluated: clarity, fullness, brightness vs dullness, hardness/sharpness vs softness, spaciousness, nearness, extraneous sounds, loudness. Visual analog scales (VAS) are used for each dimension and the patient has to score the dimension on a 10 cm VAS (between 0 to 10).

The Gabrielsson scale (1988) is used to evaluate perceived sound quality as a multidimensional phenomenon, that is composed of a number of separate perceptual dimensions. Eight perceptual dimensions are evaluated: clarity, fullness, brightness vs dullness, hardness/sharpness vs softness, spaciousness, nearness, extraneous sounds, loudness. Visual analog scales are used for each dimension and the patient has to score the dimension on a 10 cm VAS (between 0 to 10).

The speech recognition in quiet is evaluated with syllabic list of 40 phonemes. The patient has to recognize 21 syllables. The phonemes are scored: each good answer is scored 1 yielding a total between 0 and 1 (or 0% and 100%).

The speech recognition in quiet is evaluated with syllabic list of 40 phonemes. The patient has to recognize 21 syllables. The phonemes are scored: each good answer is scored 1 yielding a total between 0 and 1 (or 0% and 100%).

This test aimed to determine the smallest perceptible difference in F0 between two stimuli for various baseline values of F0. An adaptive procedure is used.

This test aimed to determine the smallest perceptible difference in F0 between two stimuli for various baseline values of F0. An adaptive procedure is used.

The test stimuli of the melodic contour test (Galvin et al. 2007) are melodic contours composed of 5 notes of equal duration whose frequencies corresponded to musical intervals. Nine distinct musical patterns have to be identified by the patient. Each good answer is scored 1 yielding a total between 0 and 1 (or 0% and 100%).

The test stimuli of the melodic contour test (Galvin et al. 2007) are melodic contours composed of 5 notes of equal duration whose frequencies corresponded to musical intervals. Nine distinct musical patterns have to be identified by the patient. Each good answer is scored 1 yielding a total between 0 and 1 (or 0% and 100%).

Inclusion Criteria: Adult patient (≥ 18 years old) speaking French Patient who fulfils the criteria for cochlear implantation Exclusion Criteria: - Retro-cochlear pathology: auditory neuropathy, vestibular schwannoma