Harmful.

Wearing headphones frequently to sleep can cause mild deafness. In daily life, you should avoid being exposed to noisy environments for long periods of time. Especially for people who often wear headphones to listen to music, the volume should not exceed the maximum volume of 60, and should not exceed 60 minutes in a row. Try not to listen to music with headphones in noisy environments. Headphones will cause less hearing damage than earplugs.

Extended information:

Experts say that bad ear-using habits and long-term exposure to noise environments may cause hearing loss. These noises can be said to be everywhere, such as the sound of cars on the street, the sound of impact drilling at construction sites, etc. At the same time, young people who like to talk loudly in noisy places such as karaoke can also damage their hearing. Symptoms such as tinnitus and dizziness are often early signs of hearing loss. As symptoms of hearing loss continue to worsen, these high-risk individuals are likely to lose their hearing completely. If citizens find that they have hearing loss, it is best to see a doctor within a week. Hearing damage is irreversible and is basically difficult to cure if it lasts for more than three months.

Reference materials: Zhuzhou News Network - Frequent wearing of headphones to sleep causes mild deafness. Hearing loss has become an "urban disease"