often resembled a French dialect. The broader study of contact varieties within a society is called linguistic ecology. Sign languages Contact between sign languages Language contact can take place between two or more sign languages, and the expected contact phenomena occur: lexical borrowing, foreign "accent", interference, code switching, pidgins, creoles, and mixed systems. Contact between sign languages and oral languages Language contact is extremely common in most deaf communities, which are almost always located within a dominant oral language culture. However, between a sign language and an oral language, even if lexical borrowing and code switching also occur, the interface between the oral and signed modes produces unique phenomena: fingerspelling, fingerspelling/sign combination, initialisation, CODA talk, TDD conversation, mouthing and contact signing. See also Areal feature Language transfer Code-switching Pidgin Creole language Lingua franca Mixed language Calque Loanword Metatypy Nahuatl-Spanish Contact Phono-semantic matching Post-creole speech continuum Sprachbund Language island Lexical gap Diffusion Linguistic anthropology References Notes General references Hickey, Raymond (ed.), The Handbook of Language Contact (Malden, MA: Wiley-Blackwell 2010) Sarah Thomason and Terrence Kaufman, Language Contact, Creolization and Genetic Linguistics (University of California Press 1988). Sarah Thomason, Language Contact - An Introduction (Edinburgh University Press 2001). Uriel Weinreich, Languages in Contact (Mouton 1963). Donald Winford, An Introduction to Contact Linguistics (Blackwell 2002) . Ghil'ad Zuckermann, Language Contact and Lexical Enrichment in Israeli Hebrew (Palgrave Macmillan 2003) .