Jack steadily progressed, noticeably through increased eye contact and a louder voice.
In this sentence, which one is grammatically right, 'noticeable' or 'noticeably'?
Here, I'd like to express that I noticed his progress and change from our increased eye contact and his louder voice when he gave a speech in English. He is an English language learner who is at beginner level. And I am his English tutor.