Today, despite the implementation of hearing screenings for new born babies, there are still late diagnoses of hearing impairment among school-age children. Results have revealed that children who participate in auditory-verbal therapy (AVT) can achieve linguistic skills at the same level as their hearing peers. Voice quality seems positively affected, placing young children with cochlear implants (CIs) in the normal range for receptive vocabulary development. In contrast, reading skills don’t seem to benefit as much from AVT, although it does seem to contribute to children’s integration into mainstream society. Despite the recorded speech and language improvements of young children with CIs, the aim of AV therapy is still not fulfilled. AV therapy can be seen as the best clinical practice for young children with CIs till now, but the lack of well-controlled studies is a concern.
The new-born screening programmes and provision of early habilitation programmes among identified children makes oral language the most selected option for families and caregivers, at least for more than 90% of cases who have hearing parents (Mitchell and Karchmer, 2004). The choice of sign language (manual based) is mainly made up of the other 10% of children who have deaf parents, or children who do not have the requirements to develop oral language. However, Punch and Hyde (Punch & Hyde, 2011) underline the need for parents to get more informed on communication methods, as well as schooling options, to support their selection.
Aside from the two basic approaches, there are also some alternatives that combine techniques and follow slightly different methodologies. Some are visual-based (sign language), and others are auditory driven (AVT and AV therapies). There are also programmes that combine both main approaches (total communication, bilingual/bicultural) to achieve maximum results in communication. As such, aural/oral programmes promote the use of residual hearing. They also promote speech-reading techniques to develop spoken language. In comparison, the total communication approach is based on the use of sign language and auditory and oral techniques. Audition is crucial for AVT, and residual hearing is a necessary component for the acquisition of spoken language without the use of additional cues, like speech reading or gestures.
Research found in the PubMed database in the last 10 years has concluded that there are some serious effects of AVT on crucial aspects of the linguistic skills of CI children. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the research question of the current systematic review was: “What is the effectiveness of AVT in the speech and language development of children with cochlear implants?”
The systematic review was designed based on PRISMA guidelines and Critical Appraisal of Treatment Evidence (CATE) checklist. Specific keywords were chosen based on the research question and searched on the PubMed database. All searched papers were analysed based on specific exclusion criteria and classified into four evidence levels.
Inclusion Criteria
The search process was based on the inclusion of specific keywords, such as “auditory verbal therapy—AND—cochlear implant.” Peer-reviewed papers were considered eligible if they were published in the last decade in English and were concerned with children from birth up to 17 years old. The search included all types of studies such as original articles; clinical trial phases I and II; classical articles; randomised controlled trials; and comparative studies, and all had to be available as “full texts.” The study located peer-reviewed studies that were published in the last ten years only. There was data that had been published before the selected time period, but the present hearing technology is not similar to the CI technology of a decade ago. This systematic review discussed only studies that deal with the effects of AVT on auditory perception and expressive and receptive language.
Exclusion Criteria
The present search strategy excluded papers concerning adult population or non-humans. Similarly, any reviews or papers not published in peer-reviewed journals were excluded. Studies with a different aim other than to shed light on the effectiveness of AVT were also excluded. Other papers were excluded if they had studied the effectiveness of the AVT approach, but not with CI recipients. The search strategy also excluded papers about the effectiveness of AVT in families, but not with regards to communication. More studies were excluded if their participants received AVT, but the effectiveness of the approach was not studied.
The initial search for the term “auditory verbal therapy” gave 2364 articles from 1951 to 2020. The use of the term “cochlear implant” decreased the outcome to 204, while the time restriction for the inclusion of papers published in the last decade resulted in 132 articles. The final total number of 8 articles was based on the aforementioned exclusion criteria.
Discussion of AVT in children with CI
The search revealed increased research interest in developing habilitation strategies for children with hearing impairments. The limited evidence on the effectiveness of AVT is enriched with new data, and this is one of the most important clinical implications this study brings. Future counselling for parents who want their infants with hearing impairment (HI) to acquire and develop spoken language, and speech pathologists who provide the service, should take these new research outcomes into account. Although recent evidence from the published papers that were reviewed revealed the positive role of AVT with regard to the speech and language skills of CI children, it is still difficult to generalise. AVT can be seen as a tool for CI children to catch up with their normal hearing (NH) peers, but future studies need to clarify many weaknesses in the process of evidence and validity.
This systematic review reported the outcomes of eight peer-reviewed studies, published on the PubMed database, on the effectiveness of AVT in the communication skills of children with CIs. AVT can be seen as an instructional approach suitable for hearing loss (HL) children. To our knowledge, this is the latest systematic review of research published over the last 10 years about the effectiveness of AVT.
Retrospective and longitudinal studies revealed statistically significant improvements in both expressive language and auditory comprehension based on AVT. There is also a lack of well-controlled studies addressing the use of AVT. On the other hand, a lack of these studies does not prevent us from concluding that AVT is an effective intervention in the habilitation of children with cochlear implants based on the aforementioned data. AVT has already been proved to be an effective approach for these specific individuals with cochlear implants.
