[ethmarks]

But tonal information can be parsed without lexical understanding and vice versa.

Somebody cursing in French can still be interpreted as anger even if you don't understand French, and written profanity can still be interpreted as anger even if you didn't hear it spoken.

Tone and language do complent each other, but neither is a prerequisite for the other like your book analogy would suggest.

[foofoo12]

> but tonal information can be parsed without lexical understanding

Parsed perhaps, but it's so context sensitive that it's not useful, save for extremities. The same tone of voice can have so many meanings based on what's actually being said and yet another if you add context.