By nature, pronunciation and listening go hand in hand. A toddler learns to speak by listening to the sounds in his surroundings first. So, it is not impossible that a toddler, who hears only Japanese language, even though he is in the Philippines, will be able to speak Japanese and understand it as well.
Yes. Improved listening ability should mean improved pronunciation and vice versa. But, this is not true for all. The learner’s personality, which plays a vital role in the learning process, may determine his future in this aspect. What I really mean is that it boils down to the learner’s capacity and his openness to accept changes. He needs to be like a toddler; ready and open. However, this is not to say that when one doesn’t have a good English Pronunciation, one can’t improve one’s listening ability. It is just that in general, among the people I know at least, when one hears well, one sounds well.