Wearing only one headset is usually not too bad for the ear, but if you wear only one headset for a long time, or turn the sound up too loud when wearing only one headset, it may lead to hearing loss in one ear and noise hearing loss, and may even lead to loss of noise hearing in the long term.
The human ear can usually feel the sound wave frequency is between 20000 to 200000Hz, hearing is generally more sensitive to 500~1000Hz sound wave frequency, and insensitive to 2000~4000Hz noise. If you use headphones for a long time will probably damage the hearing of high-frequency sound waves (2000-4000Hz).
And wearing only one headphone for a long time, or turning up the sound too loud when wearing only one headphone, will possibly damage the hearing of that ear and reduce the sensitivity to noise. Therefore, when wearing headphones on a daily basis, it is important to pay more attention to the length of time you use them and the volume of sound you use to avoid damage to your ears.