Context: The principles of phonological analysis can be applied independently of modality because they are designed to serve as general analytical tools, not language-specific ones. The same principles have been applied to the analysis of sign languages (see Phonemes in sign languages), even though the sub-lexical units are not instantiated as speech sounds.

Question: Instead of being language-specific what kind of tools are the principles of phonological analysis designed to be?
Answer: general analytical tools

Question: What other types of language have the phonological analysis principles been applied to?
Answer: sign languages

Question: What are the principles of phonological analysis able to be applied separately from?
Answer: modality

Question: In sign languages what are not represented as instances of speech sounds?
Answer: sub-lexical units

Question: Instead of being language specific what kind of tool is sign language designed to be? 
Answer: Unanswerable

Question: What other types of language have the speech sound principles been applied to 
Answer: Unanswerable

Question: What are the principles of sign language able to be applied separately from?
Answer: Unanswerable

Question: In sign laguages what are not represented as instances of analytical tools?
Answer: Unanswerable

Question: What can be applied depending on modality?
Answer: Unanswerable