Exercitia, Pars 1 (Familia Romana), Capitulum 27, Exercise 1, number 7

Hello, I’m going through the answers to Capitulum 27, exercitium 1, for Familia Romana. The answers to number 7 (In loquendo _____ utimur, _____ utimur in audiendo) are

“lingua” (ablative sing) and “auribus” (ablative plural).

I’ve been looking through my grammar’ and if I’m correct “utimur” is a deponent verb that is first person plural, so shouldn’t it be “linguis”? or is “utimur” a typo and should be “utitur”? Just a bit confused.

I don’t have the book but I expect it’s all right. In speaking we use the tongue, in listening we use the ears. OK?