Coding strategies with different numbers of fine structure channels
23 April 2019 (online)
With its current coding strategies, MED-EL tries to make temporal information of a sound signal available via the fine structure for the CI user. This should improve both speech understanding in noise and sound and music perception. The aim of this study is to compare the latest high-sample-rate fine-structure strategy (FS4-HR) with the first generation of fine-structure strategies (FSP) in terms of speech understanding, perception of music and sound.
Material and method:
The study included CI users who used the FSP strategy for at least six months. The conversion of patients from FSP to FS4-HR was carried out for half of the patients on the first and for the second half on the third study visit. The speech understanding tests (Freiburger Einsilber, HSM, OLSA) as well as sound and music assessments were compared on five dates within six months using both coding strategies.
Twenty patients were included into the study, 17 completed and three discontinued. The final results show no significant differences between the two coding strategies in terms of speech understanding and individual sound assessment. Both strategies show a good discrimination with respect to frequency-filtered music signals compared to normal hearing.
The coding strategy FS4-HR offers the user more fine-structure information than FSP, but these did not lead to better hearing performance in the tests performed. On an individual basis, it is therefore necessary to decide which coding strategy to choose, because it is not possible to make a recommendation per se.