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

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.