This study investigated effects of profound hearing loss on mother-infant interactions before and after cochlear implantation with a focus on maternal synchrony, complexity, and directiveness. Participants included two groups of mother-infant dyads: 9 dyads of mothers and infants with normal hearing; and 9 dyads of hearing mothers and infants with profound hearing loss. Dyads were observed at two time points: Time 1, scheduled to occur before cochlear implantation for infants with profound hearing loss (mean age = 13.6 months); and Time 2 (mean age = 23.3 months), scheduled to occur approximately six months after cochlear implantation. Hearing infants were age-matched to infants with hearing loss at both time points. Dependent variables included the proportion of maternal utterances that overlapped infant vocalizations, maternal mean length of utterance, infant word use, and combined maternal directives and prohibitions. Results showed mothers’ utterances overlapped the vocalizations of infants with hearing loss more often before cochlear implantation than after, mothers used less complex utterances with infants with cochlear implants compared to hearing peers (Time 2), and mothers of infants with profound hearing loss used frequent directives and prohibitions both before and after cochlear implantation. Together, mothers and infants adapted relatively quickly to infants’ access to cochlear implants, showing improved interactional synchrony, increased infant word use, and levels of maternal language complexity compatible with infants’ word use, all within seven months of cochlear implant activation.