Stapedius reflex measurements in open sound-field in children using MED-EL cochlear implant systems.

OBJECTIVES: The study compared stapedius reflex thresholds during presentation of acoustic stimuli in an open sound field (sf-SRT) in paediatric cochlear implant (CI) users with the MED-EL system and children with bilateral normal hearing sensitivity. DESIGN: The sf-SRT was measured using open-sound-field acoustic stimulation with narrow-band noise (NBN) centred at 0.5, 1, 2, and 4 kHz, and broad-band noise (BBN). The sf-SRTs were measured twice in two different sessions. STUDY SAMPLE: Nineteen unilateral paediatric CI users and twenty children with bilateral normal hearing sensitivity, with an age range from 3 to 12 years. RESULTS: The sf-SRT levels ranged from 65 to 103 dB HL and 70 to 90 dB HL across stimulus types in the CI and normal-hearing groups, respectively. Mann-Whitney U test revealed that the CI group had significantly higher sf-SRT levels for 2 kHz NBN than the normal-hearing group. In the CI group, repeated-measures ANOVA revealed significantly higher sf-SRT levels for NBN centred at 2 kHz than for 0.5 kHz and BBN. The sf-SRT measurements were reported to be reliable in the CI group. CONCLUSION: High test-retest reliability was demonstrated, supporting the use of sf-SRT measurements to confirm upper stimulation levels in paediatric CI users.