Hearing children of deaf parents are often special bilinguals: they acquire both a sign language as well as a spoken language simultaneously as a first language; the spoken language usually from their deaf parents as well as from their (hearing) extended family and/or from other hearing persons (Bishop & Hicks 2009).
Many bilingual people who learn two (or more) languages as a first language are common users of both languages in their daily life (Grosjean 2010), to such an extent that they even sometimes use the two languages within one utterance. This is called code-switching or code-mixing, where the bilingual sequentially uses two languages, sometimes even in one utterance, e.g.

“Marc, savonne-toi. You haven’t used soap for a week!” (Grosjean 2010: 57)

Of course, it is not possible in spoken languages to simultaneously pronounce two words in two languages, they have to be sequentially uttered. Signs and words, however, can be produced simultaneously, as in the following example:

Spoken: “ I don’t think he would really live”
Signed: NOT THINK REALLY LIVE (Emmorey et al. 2008: 14)

The combinations of signs and words provide us with insights into how bimodal bilingual people code-blend two languages simultaneously (Emmorey et al. 2005) and how hearing children of deaf parents acquire two languages simultaneously (Baker & Van den Bogaerde 2014) and to what extend they use code-blending.
Research on bimodal bilingualism is important for many deaf children too, especially those children whose success in spoken language acquisition is not very high and who are offered sign supported speech by teachers who are not fluent in sign language but who use and mix spoken language with signs. These children sometimes neither acquire the spoken language (because they don’t have full access to it) nor a sign language, because:

“First, CIs as a standalone technology do not provide accessible language. Second, health professionals typically either advise against or do not encourage giving a sign language to an implanted child, thus cutting them off from an accessible language during the years crucial to first language acquisition.” (Humphries et al. 2012)

In this course we will study the literature on bimodal bilingualism, and gain insight into how the simultaneous use of words and signs needs to be formulated as input to deaf children with a cochlear implant in such a way, that they improve both the acquisition of the spoken language as well as the sign language.

References
Bishop, M. & S.L. Hicks (eds.). 2009. Hearing, Mother Father Deaf. Hearing people in Deaf families. Series: The Sociolinguistics in Deaf Communities Series, ed. Ceil Lucas. Washington: Gallaudet University Press.
Emmorey, K., H. Borinstein, R. Thompson & T. Gollan. 2008. Bimodal Bilingualism. In M. Bishop & S.L. Hicks (eds.). Hearing, Mother Father Deaf. Hearing people in Deaf families, pp. 3-43. Series: The Sociolinguistics in Deaf Communities Series, ed. Ceil Lucas. Washington: Gallaudet University Press.
Humphries, T., P. Kushalnagar, G. Mathur, D.J. Napoli, C. Padden, C. Rathmann & S. Smith. 2012. Cochlear Implants and the Right to Language: Ethical Considerations, the Ideal Situation, and Practical Measures Toward Reaching the Ideal.
http://www.intechopen.com/books/cochlear-implant-research-updates/the-right-to-language-ethical-considerations-ideal-situation-and-practical-measures-toward-reachi