The thesis work focuses on the assessment of speech intelligibility of children with cochlear implants in real complex acoustic scenarios, which include both competitive sound environments (i.e., with reverberation and noise) and the use of face masks that modify speech intelligibility towards a listener. The research is inspired by the recent events related to the global pandemic, as well as by the need of ensuring optimal acoustic scenarios for the support of auditory abilities especially for hearing impaired listeners. On the one side, the dramatic spread of the Coronavirus disease made it necessary face masks in public and private spaces. Although the use of face masks is needed to prevent the spreading of Coronavirus, several studies have already shown their negative effects on speech intelligibility (SI) and comprehension due to the coverings’ acoustic attenuation.