Wear headphones to listen to music on the subway. Be careful to prevent hearing loss.
Do not use them continuously for more than 1 hour. Whether children, teenagers or adults, when using headphones, the volume should not exceed 60 decibels. If you do not change your listening habits and the hearing loss worsens or develops from high frequencies to mid-low frequencies, it may cause permanent hearing loss and you may even need to use hearing aids to assist hearing. "To protect hearing, prevention is more important than treatment."