How do tone languages assign phonemic tones to loanwords from non-tone languages? For example, does such assignment vary according to the phonological context in each loanword? Alternatively, does each tone language have a typical pattern of tones that it assigns to such loanwords? Are there such things as strategies for such tone-assignment that are common across contour tone languages? Across register tone languages? Across both types?
Studies of loanword adaptation have largely focused on segmental adaptation and hence not much compiled information is available on suprasegmental adaptation. The most comprehensive overview I'm aware of is Kang's 2010 Lingua article, Tutorial overview: Suprasegmental adaptation in loanwords. I recommend looking at the article if you have access, but here's a sampling with specific cases from accessible papers:
- Stress to high tone: English to Mandarin (Silverman 1992)
- Stress to rise-fall contour: English into Yoruba (Kenstowicz 2006)
- Default tone(s) for loanwords: French into Vietnamese (Barker 1969)
- Syllable shape to tone: English into White Hmong (Golston and Yang 2001)
- Voiced/voiceless onset to low/high tone: English to Tibetan (Hsieh and Kenstowicz 2006)
As the implementation of tone across languages differs considerably, it's also worth wondering about adaptation between tone languages. The Hsieh and Kenstowicz paper mentions that Tibetan adaptations of Mandarin words, for example, ignores the original tone in favor of the voiced/voiceless distinction.