Bellering, which is usually described as a loud and unpleasant sound, can have many antonyms depending on the context in which it's used. For example, the opposite of bellowing, which is another word for bellering, could be whispering or murmuring. Alternatively, if the meaning is taken in terms of animal sounds, the antonyms could include chirping, tweeting, or singing. In a more general sense, words like calming, soothing or quiet could also be antonyms for bellering. Ultimately, the antonym for bellering would vary based on the situation and the intent behind the usage of the term.