It is tempting to identify sentence tokens with certain noises or inscriptions. But this is mistaken, if we want meaning and truth to be a function of the sentence token. For it is easy to imagine a case where a speaker with a single noise says two things, one a truth in language L1 and the other a falsehood in language L2, to two different interlocutors. It's kind of hard to come up with examples using actual languages, except of the one word sort. My favorite there would be pointing at a bottle and saying to two people, one a speaker only of English and the other a speaker only of German "Gift", and each ignorant of the other's presence (we can imagine them on either side of a divider). To the speaker of English, one has said that the bottle is a present; the speaker of German has been warned that it is poison. A different kind of example can be produced using ambiguity and context. If I've just been talking with Fred about rivers and with George about finances, and neither was a party to the other conversation, I can say: "I was by the bank yesterday", deliberately telling Fred that I was by the riverbank yesterday and telling George that I was visiting a financial institution. The two claims might be both true, or both false, or one true and the other false.
So if we want sentence tokens to play the role of resolving ambiguity, taking care of indexicals, etc., so that meaning and truth would be a function of the token, the tokens can't be noises and inscriptions. They could be noise (or inscription) and intention pairs, or they could be utterings (maybe in each of my above cases, I deliberately do two utterings with one same noise, just as I might do two mosquito killings with one well-placed slap), or they could be noise and understanding pairs (if we prefer to locate meaning on the side of the listener), or they could be acts of hearing.