CLABOX. Audiological Evaluation Tool for Remote Assessment of Cochlear Implants

Cochlear implants (CI) are now widely accepted as an effective treatment for profound deafness. Several commercial devices are currently available and technological resources are constantly updated. However, we still face difficulties in the standardization of evaluation of CI users, such as large variation in the acoustics of test environments, use of different types of speech recognition materials, inconsistent use of noise in speech tests, and absence of normality criteria. The CLABOX was developed in an attempt to standardize audiological tests and allow comparisons between cochlear implant user outcomes among centers and countries in Latin-America. The CLABOX is an audiological evaluation tool written in Matlab designed to provide a direct connection between the computer and the cochlear implant via a commercial audio interface (Presonus AudioBox iOne). This feature allows an evaluation condition independent of local acoustic conditions or the availability of good sound stimuli, as the CI external microphone can be turned off during tests and all audio files used for testing are pre-recorded. CLABOX offers the following sound stimuli: (1) pure tones to verify the CI calibration; (2) Ling sounds, which are language independent and can be used to evaluate detection and identification in both adults and children; and (3) sentences with or without additive noise to mimic HINT conditions (fixed or adaptive), which can be used to evaluate speech recognition skills. The CLABOX environment was compared to measurements in a sound booth. Fifty individuals with cochlear implants (CIs), 33 adults and 17 children, were included. For speech recognition in noise, averages were better in the CLABOX; for pure tone threshold, they were higher in the CLABOX; and for Ling sounds, there was no significant change in the categories between sound booth and CLABOX, suggesting that the CLABOX is an effective tool to assess pure tone and speech recognition tests.