athāpi janakatvamabhyupagamyate śabdasya tathāpi doṣa iti darśayann āha tadutpattāvityādi / seti tadutpattiḥ /
Even if the productive nature of sound is accepted, there is still a fault - this is what [the author] shows by saying "in the case of its production" etc. The word 'sā' refers to that production.