Kester, there are very few studies that directly compare these groups of children, and those that do often group together deaf children who are exposed to any form of manual communication (ASL, Signed Exact English, baby signs, etc), without considering the age at which they began acquiring it, and also without actually assessing their proficiency in a natural sign language like ASL. So there are not a large number of well controlled studies. Are you interested in a particular domain? In the work I am familiar with, deaf children who have been exposed to fully accessible language (generally ASL) from birth perform very similarly to hearing children the same age.

Hai Kester, its a good question. But according to my view its totally depend on the child. In other word we can say that the decision should be individuals basis. every child is different and how he is going to take ASL as a part of his communication skill can also effect use of ASL in childrens with cochlear implant. Like for example some children, mat get fully dependent on ASL, in that case the purpose of putting cochlear implant and advantage of auditory stimulation will be limited. But on the other hand, a child with CI can take ASL as a tool for better communication in addition to auditory stimulation. So, its very individuals specific. So, please keep child in mind before taking decision. You can also go through few articles in this area.    As sign language use is taken under consideration for use with implanted children, it is necessary to acknowledge there are various categories of sign use for students with implants, and that the role of sign language for a child may change at various stages post-implantation. Some children may start out using sign language as a foundation to early language development, with sign use diminishing as spoken language skills emerge. Some children may continue to utilize a combination of sign and spoken language. Some students may focus on spoken language with some sign language as a support. Some students may be sign language communicators with spoken language developed as a support to sign use. Where a child falls on the auditory-visual continuum is unique to the characteristics of each child, and planning for each child must be done on an individual basis.

The important consideration with this question is at what age are you going to assess the patient's progress with regard to language acquisition.  In my experience ASL + auditory verbal results in a bilingual child/young adult.  They may lag in some of the early stage assessments of language development (auditory-verbal development), but over the long term they will be highly beneficial members of the hearing and deaf communities.  They are bilingual which can be a very useful skill with regard to future employability and engagement with deaf individuals socially and professionally.  So, from a clinical standpoint I don't discourage ASL and I have this discussion with interested parents regarding reasonable expectations and time course to speech and language acquisition.  Part of my bias is a fascination with ASL and the ability of deaf individuals to communicate so fluidly using sign.  I view these children as bilingual +, and many of them go on to speak multiple languages and find language acquisition easier in late childhood and young adulthood very similar to typical hearing bilingual children.  This is all opinion, and I would love any real evidence in support!  Good topic, thanks.

Great discussion!  This recent paper is with adult L2 ASL learners but offers an interesting perspective on plasticity.

Article Bimodal bilingualism as multisensory training?: Evidence for...

Thank you for adding this article. I am actually gathering information to educate parents and public school districts about the benefits of bilingualism versus monolingualism for d/hh children. I already have ties to the VL2 center at Gallaudet Univcersity. I'm searching for other studies around the world  that might replicate or supplement their findings. Yes, I am searching more for studies on younger children where language acquisition occurs at a more typical age/rate.

I understand that each child is different; however, having multiple languages is still more beneficial than being monolingual.

This source can be useful. It's downloadable from: http://www.cslds.org/v3/publications.php?page=2

Li, Qun., Tang, Gladys., Yiu, Chris., & Lam, Scholastica. 2014. Deaf students’ literacy development in the SLCO Programme. Paper presented at the 2014 Symposium on Sign Bilingualism and Deaf Education, The Chinese University of Hong Kong. Jun, 2014.

Muchas gracias!