Early intervention is not officially implemented in Thailand. The shortage of practitioners, the inaccessibility of early intervention services, and the lack of parental involvement extremely deprive opportunities for children who are deaf and hard of hearing to develop language and communication within the critical period. This dissertation aimed to explore an intervention approach that practitioners can use to encourage and empower parents' roles and responsibilities, as well as improve the children's language outcomes. The objectives in this dissertation study were to explore (a) how online parent training in the modified Teach-Model-Coach-Review Instructional approach can be implemented to improve the parents' use of language expansion during routine-based activities with their child with cochlear implant(s); (b) how parents' use of language expansion develop their child's spoken language, and (c) how parents perceive the benefits of the intervention. The multiprobe baseline across participants was used to examine the functional relation between the online parent training and the parents' use of language expansion. Four Thai parent-child dyads from different provinces participated in this study. Parents were trained at their homes through video conferencing, focusing on the use of language expansion strategies (e.g., labeling, describing, explaining, pretending, projecting, talking about feelings, talking about the future, correcting grammatical errors). Parent-child interactions were video-recorded for data collection. Both the parent's and child's data were graphed and visually inspected. The meaningfulness of the study from parents' perspectives was explored through semi-structured interviews. A functional relation between the parent training and the increased frequency of parents' use of language expansion during routine-based activities was found. Moreover, parents reported their satisfaction towards the online training, language expansion strategies, and their child's language outcomes. However, these satisfiable results contain limitations that are emphasized for future researchers to carefully consider before replication. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]