Frequency and intensity discrimination in children with cochlear implants

Abstract

Frequency discrimination underlies more complicated auditory activities like speech comprehension and interpretation. However, intensity differences indicate how far apart noises are. This study aimed to evaluate and compare results of frequency modulation and difference limen for intensity in children with cochlear Implants (CI) as well as normal hearing children. This case–control work was performed on 40 children, aged from 5–18 years, divided into two equal groups: a study group with unilateral CI and a control group with normal peripheral hearing. All patients were subjected to otological examination, audiological evaluation, frequency modulation difference limen (FMDL) and difference limen for intensity (DLI) tests. Patients with CI, as compared to normal hearing (NH) subjects, required significantly higher frequencies to discriminate FMDL and DLI respectively (P value = 0.001). At 2000 and 4000 Hz: FMDL had a significant diagnostic power for patients with CI (AUC = 0.980, 0.998 respectively, P < 0.001), at cut off 1.5, with 100% sensitivity and 100% specificity. While, at 4000 Hz: DLI had a significant diagnostic power for patients with CI (AUC = 0.999, P < 0.001), at cut off 1.5, with 100% sensitivity and 100% specificity. A statistically substantial variation was observed among CI and NH children in FMDL and DLI at all frequencies tested. Patients with CI required significantly higher frequencies to discriminate as compared to NH subjects. Frequencies at 2000 Hz and 4000 Hz possess the best specificity and sensitivity of FMDL. While frequency 4000 Hz possess the best specificity and sensitivity of DLI.