Hearing loud noises while sleeping will be frightened, may be due to the surrounding environment is strange, excessive work pressure, neurasthenia and many other factors. 1. Strange surroundings: If the human adaptability to the environment is too poor, in an unfamiliar environment, will lead to the human body is too nervous, thus affecting the quality of sleep, so that sleep is susceptible to the stimulation of the outside world and the sound of the startle. 2. Excessive work pressure: excessive work pressure will lead to the human body in an extremely tense state of mind, which will lead to the body by the outside world and the impact of the sound of shock. 3. neurasthenia: long-term tension or pressure, will cause the human body’s neurasthenia, which leads to the human body’s physiological disorders, so that sleep will be affected by the sound and frightened. As there are many reasons for hearing loud noises and being frightened while sleeping, it is therefore recommended to go to the hospital in time for treatment.