Comparison of different speech coding strategies using a disability-based inventory and speech perception tests in quiet and in noise.

OBJECTIVE

Intraindividual comparison of two cochlear implant speech coding strategies implemented in the Nucleus 24M system (SPEAK versus ACE). Reasons for subjective preference were evaluated using a combination of speech perception scores and a disability-based inventory.

STUDY

DESIGN

Cross-over study with two groups of cochlear implant subjects, assigned to first receive ACE or SPEAK strategy.

SETTING

Cochlear implant program.

SUBJECTS: Twelve postlingually deaf adults using a Nucleus 24M cochlear implant system.

INTERVENTION: Subjects consecutively used the two different speech coding strategies and completed speech perception tests in quiet and in noise and a disability-based inventory (Abbreviated Profile of Hearing Aid Benefit).

MAIN OUTCOME MEASURES: Individual differences between the two different speech coding strategies and the relation with subjective strategy preference.

RESULTS

The ACE strategy produced somewhat better speech recognition scores in quiet and in noise, although the difference in the scores in noise did not reach the 95% level of significance. The first coding strategy chosen did not affect the results or subjective preference. Preference according to the APHAB results were not a priori in conformity with the speech recognition scores.

CONCLUSION

Most subjects preferred the ACE strategy. Subjective preference was in agreement with the APHAB results in three subjects, in agreement with speech recognition in two subjects, and in agreement with both in seven subjects. The present results support the use of both speech recognition tests and questionnaires to evaluate different speech coding strategies.