Remote self-testing for adult cochlear implant users: the effect of wireless streaming on speech recognition in noise

Objectives: Wireless sound transfer methods for cochlear implant sound processors have become popular for remote self-assessed hearing tests. The aim of this study was to determine (1) spectral differences in stimuli between different wireless sound transfer options and (2) the effect on outcomes of speech recognition tests in noise. Design: In study 1, the frequency response of different streaming options (Phonak Roger Select, Cochlear Mini Mic 2+, telecoil and Bluetooth connection) was measured by connecting headphones to CI sound processors. Study 2 followed a repeated measures design in which digits-in-noise (DIN) tests were performed using wireless streaming to sound processors from Cochlear, Advanced Bionics, and MED-EL. Study Sample: 20 normal hearing participants. Results: Differences in frequency response between loudspeaker and wireless streaming conditions were minimal. We did not find significant difference in DIN outcome (F4,194 = 1.062, p = 0.376) between the wireless transfer options with the Cochlear Nucleus 7 processor. No significant difference in DIN outcomes was found between Bluetooth streaming and the loudspeaker condition for all of the three tested brands. The mean standard error of measurement was 0.72 dB. Conclusions: No significant differences in DIN test outcomes between wireless sound transfer and the reference method were found.