Learning vocabulary through listening is one type of learning through meaning-focused input. Learners would need at least 95% coverage of the running words in the input in order to gain reasonable comprehension and to have reasonable success at guessing from context (https://www.cambridge.org/core/books/abs/learning-vocabulary-in-another-language/vocabulary-and-listening-and-speaking/E1AACDB39B0F72636009BC910FD455C5