Effect of test realism on speech-in-noise outcomes with bilateral cochlear implant users
* Presenting author
Current speech intelligibility tests conducted in the laboratory follow oversimplified methods whereby neither the target speech nor the interfering noises resemble what a person encounters in their daily lives. This study explores the effect of the realism of the target speech and noise on word recall performance of bilateral cochlear implant users. Three different test paradigms are compared: (1) anechoic BKB-like sentences presented in babble noise, (2) reverberant BKB-like sentences presented in three-dimensional recordings of actual noisy situations, and (3) a variation of the second test where the sentences were taken from natural effortful conversations. All the tests were conducted by means of a spherical loudspeaker array located inside an anechoic chamber. The comparison was conducted at two different SNRs: 1.4 and -2.2 dB. Speech intelligibility results from eleven adult CI users were consistently highest in the first test and lowest in the third test. These results indicate that participants could more easily deal with babble noise than with more realistic noisy situations, and that they could understand more easily BKB-like sentences than more realistic speech. The findings of this study highlight the importance of improving the realism of speech-in-noise tests to provide outcomes with increased ecological validity.