The two objectives of this single-subject study were to assess how an FM system use impacts parent-child interaction in a noisy listening environment, and how a parent/caregiver training affect the interaction between parent/caregiver and child. Two 5-year-old children with hearing loss and their parent/caregiver participated. Experiement 1 was conducted using an alternating design measured three communication behaviors (e.g., child's vocalization, parent/caregiver's initiation, and parent/caregiver's response) across four listening conditions (e.g., HA+Quiet, HA+Noise, FM+Quiet, and FM+Noise). Experiment 2 was conducted using a comparison within and between conditions to re-measure the communicative behaviors across the listening conditions after the parent/caregiver training. Findings of this study point to three major conclusions. First, FM system use (i.e., FM-only mode) facilitated FM01 child's ability to maintain same level of interaction in a noisy as good as in a quiet environment. Second, parent/caregiver training enhanced the impact of FM system use for one child (FM01), although parent/caregiver initiation increased for both. Third, it is important to verify the function of both FM system and HA microphones to ensure access to FM advantage.