Bimodal bilingualism

Bimodal bilingualism refers to an individual or community's bilingual competency in (at least) one oral language and (at least) one sign language (oral and sign are the modes to which "bimodal" refers). A substantial number of bimodal bilinguals are Children of Deaf Adults or other hearing people who learn sign language for various reasons. Deaf people as a group have their own sign language and culture, but invariably live within a larger hearing culture with its own oral language. Thus, "most deaf people are bilingual to some extent in [an oral] language in some form". In discussions of multilingualism in the United States, bimodal bilingualism and bimodal bilinguals have often not been mentioned or even considered, in part because American Sign Language, the predominant sign language used in the U.S., only began to be acknowledged as a natural language in the 1960s (In discussions of bimodal bilingualism in the U.S., the two languages involved are generally ASL and English). However, bimodal bilinguals share many of the same traits as traditional bilinguals (those with competency in at least two spoken languages), as well as differing in some interesting ways, due to the unique characteristics of the Deaf community.

Diverse range of language competency
To be defined as bilingual, an individual need not have perfect fluency or equal skill in both languages. Bimodal bilinguals, like oral-language bilinguals, exhibit a wide range of language competency in their first and second languages. For Deaf people (the majority of bimodal bilinguals in the U.S.), level of competency in ASL and English may be influenced by factors such as degree of hearing loss, whether the individual is prelingually or post-lingually deaf, style of and language used in their education, and whether the individual comes from a hearing or Deaf family. Regardless of English competency in other areas, no Deaf individual is likely to comprehend English in the same way as a hearing person when others are speaking it because only a small percentage of English phonemes are clearly visible through lip reading. Additionally, many Deaf bilinguals who have fluency in written English choose not to speak it because of the general social unacceptability of their voices, or because they are unable to monitor factors like pitch and volume.

Denial of their own bilingualism
Like hearing oral-language bilinguals, Deaf bimodal bilinguals generally "do not judge themselves to be bilingual". Whether because they do not believe the sign language to be a legitimate and separate language from the majority oral language, or because they don't consider themselves sufficiently fluent in one of their languages, denial of one's bilingualism is a common and well-known phenomenon among bilinguals, be they hearing or Deaf.

Everyday shifts along the language mode continuum
Deaf or bimodal bilinguals, in their day-to-day lives, move among and between various points on the language mode continuum depending on the situation and the language competency and skills of those with whom they are interacting. For example, when conversing with a monolingual, all bilinguals will restrict themselves to the language of the individual with whom they’re conversing. However, when interacting with another bilingual, all bilinguals can use a mixture of the two common languages.

Unequal social status of the languages involved
As is the case in many situations of oral-language bilingualism, bimodal bilingualism in the U.S. involves two languages with vastly different social status. ASL has traditionally not even had the status of being considered a legitimate language, and Deaf children have been prevented from learning it through such "methods" as having their hands tied together. Hearing parents of Deaf children have historically been advised not to allow their children to learn ASL, as they were informed it would prevent the acquisition of English. Despite the fact that Deaf children's early exposure to ASL has now been shown to enhance their aptitude for acquiring English competency, the unequal social status of ASL and English, and of sign languages and oral languages, remains.

Lack of societal acknowledgment of bilingual community status
Since linguists didn’t recognize ASL as a true language until the second half of the twentieth century, there has been very little acknowledgment of, or attention or study devoted to, the bilingual status of the American Deaf community. Deaf people are often "still seen by many as monolingual in the majority language whereas in fact many are bilingual in that language and in sign".

Bilingual language mode: Contact signing
Because almost all members of the American Deaf community are to some extent bilingual in ASL and English, it is rare that a Deaf person will find themselves conversing with a person who is monolingual in ASL. Therefore, unless an American Deaf person is communicating with someone who is monolingual in English (the majority language), he or she can expect to be conversing in a "bilingual language mode”. The result of this prolonged bilingual contact and mixing between a sign language and an oral language is known as contact sign.

Unlikelihood of large-scale language shift
Language shift "occurs when speakers in a community give up speaking their language and take up the use of another in its place". ASL in particular, and sign languages in general, are undeniably influenced by their close contact with English or other oral languages, as evidenced by phenomena such as "loan signs" or lexicalized fingerspelling (the sign language equivalent of loanwords), and through the influence of Contact Sign. However, due to the physical fact of deafness or hearing loss, d/Deaf people generally cannot acquire and speak the majority language in the same way or with the same competency that the hearing population does. Simultaneously, Deaf people still often have a need or desire to learn some form of English in order to communicate with family members and the majority culture. Thus, Deaf communities and individuals, in contrast to many hearing bilingual communities and individuals, will tend to "remain bilingual throughout their lives and from generation to generation".

Sign–print bilingualism
The written forms of language can be considered another modality. Sign languages do not have widely accepted written forms, so deaf individuals learn to read and write an oral language. This is known as sign–print bilingualism—a deaf individual has fluency in (at least) one sign language as their primary language and has literacy skills in the written form of (at least) one oral language, without access to other resources of the oral language that are gained through auditory stimuli. Orthographic systems employ the morphology, syntax, lexical choices, and often phonetic representation of their target language in at least superficial ways; one must learn these new features of the target language in order to read or write. In communities where there is standardized education for the deaf, such as the United States and the Netherlands, deaf individuals do gain skill sets in reading and writing in the oral language of the community. In such a state, bilingualism is achieved between a sign language and the written form of the community's oral language. In this view, all sign–print bilinguals are bimodal bilinguals, but all bimodal bilinguals may not be sign–print bilinguals.

How deaf children learn to read
Children who are deaf, and employ a sign language as their primary language, learn to read in slightly different ways than their hearing counterparts. Much as speakers of oral languages most frequently achieve spoken fluency before they learn to read and write, the most successful profoundly deaf readers first learn to communicate in a sign language. Research suggests that there is a mapping process, in which features from the sign language are accessed as a basis for the written language, Similar to the way hearing unimodal bilinguals access their primary language when communicating in their second language. Profoundly deaf ASL signers show that fluency in ASL is the best predictor of high reading skills in predicting proficiency in written English. In addition, highly proficient signing deaf children use more evaluative devices when writing than less proficient signing deaf children, and the relatively frequent omission of articles when writing in English by proficient signers may suggest a stage in which the transfer effect (that normally facilitates deaf children in reading) facilitates a mix of the morphosyntactic systems of written English and ASL. Deaf children then appear to map the new morphology, syntax, and lexical choices of their written language onto the existing structures of their primary sign language.

Using phonological information
There are mixed results in how important phonological information is to deaf individuals when reading and when that information is obtained. Alphabets, abugidas, abjads, and syllabaries all seem to require the reader/writer to know something about the phonology of their target language prior to learning the system. Profoundly deaf children do not have access to the same auditory base that hearing children do. Orally trained deaf children do not always use phonological information in reading tasks, word recognition tasks or homophonic tasks; however, deaf signers who are not orally trained do utilize phonological information in word-rhyming tasks. Furthermore when performing on tasks with phonologically confusable initial sounds, hearing readers made more errors than deaf readers. Yet when given sentences that are sublexically confusable when translated into ASL, deaf readers made more errors than hearing readers. The body of literature clearly shows that skilled deaf readers can employ phonological skills, even if they don’t all the time; without additional longitudinal studies it is uncertain if a profoundly deaf person must know something about the phonology of the target language to become a skilled reader (less than 75% of the deaf population) or if by becoming a skilled reader a deaf person learns how to employ phonological skills of the target language.

Pedagogical challenges for sign–print bilinguals
Only 15% of white, 5% of African-American, and 6% of Hispanic deaf high school graduates in the United States read above the sixth-grade level. The median reading level of deaf American high school graduates is fourth grade. These concerning numbers are generally the result of varying levels of early language exposure. Most deaf children are born to hearing parents, which usually leaves a deficiency in their language exposure and development compared to children and parents who use the same modality to communicate. This group of children acquire a wide range of proficiency in a first language, which then impacts their ability to become proficient in a second (though sometimes possibly a first) language in the written modality. Children exposed to Manually Coded English (MCE) as their primary form of communication show lower literary levels than their ASL signing peers. However in countries such as Sweden which have adopted a bilingual–bicultural policy in their schools for the deaf, one sees a higher literacy rate compared to school systems favoring an oral tradition.