Evaluation and Validation of Programming the Speech Processor with Otocube (Electroacoustical Test Box for Cochlear Implant Users)

Introduction: The Otocube is an electroacoustical test box that enables audiologists to do precise measurements on cochlear implants using a soundproofed box, and allows a range of psychoacoustic tests that can be used as a fitting assistant with cochlear implant users.

Objective: To analyze the results of sound field thresholds and speech perception tests in cochlear implant users in a sound field booth and Otocube. And analyze the loudness test for fitting the speech processor.

Methods: Adult patients using cochlear implant for at least 3 months routinely attended from August to December 2013 were selected. Recorded material and sound field thresholds were tested in a booth and in Otocube. The results were statistically analyzed. The loudness test was applied before the fitting in adult patients attended in January to June 2014.

Results: The sample was nine patients, three bilateral cochlear implant users, mean age 34.6 years, three with prelingual deafness. The mean difference between thresholds was statistically different only in 1 and 6 kHz. The mean speech perception test was 50% (min: 10%; max: 100%) when performed on the audiometer and 48% (min: 0%; max: 100%) in Otocube without statistical difference. Loudness scaling identified 56,2% patients with loudness ‘out of the accepted range’ and was useful to identify the patients with difficulty to determine reliable comfort levels.

Conclusion: The performance of speech recognition and thresholds in sound field booth and the Otocube was similar, with differences only two frequencies, probably related to calibration. Loudness scaling was useful during the fitting.