It is not speculation that the brain's frontal lobes constantly guess what we should have heard based on context and experience. When we listen, we don't always hear everything that is said. Apart from sight, we cannot look once more at the object. All hearing is in real time. Qualified guesses according to Gestalt psychology happens constantly, especially in very reflexive environments. With increasing age, guessing increases due to high frequency loss and reduced ability to distinguish words/sounds in dense word/sound flow. The guessing is not always correct.