Speech assessment tool methods for speech impaired children: a systematic literature review on the state-of-the-art in Speech impairment analysis

Speech is a powerful, natural mode of communication that facilitates effective interactions in human societies. However, when fluency or flow of speech is affected or interrupted, it leads to speech impairment. There are several types of speech impairment depending on the speech pattern and range from mild to severe. Childhood apraxia of speech (CAS) is the most common speech disorder in children, with 1 out of 12 children diagnosed globally. Significant advancements in speech assessment tools have been reported to assist speech-language pathologists diagnosis speech impairment. In recent years, speech assessment tools have also gained popularity among pediatricians and teachers who work with preschoolers. Automatic speech tools can be more accurate for detecting speech sound disorders (SSD) than human-based speech assessment methods. This systematic literature review covers 88 studies, including more than 500 children, infants, toddlers, and a few adolescents, (both male and female) (age = 0-17) representing speech impairment from more than 10 countries. It discusses the state-of-the-art speech assessment methods, including tools, techniques, and protocols for speech-impaired children. Additionally, this review summarizes notable outcomes in detecting speech impairments using said assessment methods and discusses various limitations such as universality, reliability, and validity. Finally, we consider the challenges and future directions for speech impairment assessment tool research.