GreatCall Jitterbug User Manual page 198

background environment noise, noise cancelling headphones should allow
you to hear the music at lower volumes than when using earbuds.
• Limit the amount of time you listen. As the volume increases, less time is
required before you hearing could be affected.
• Avoid using headphones after exposure to extremely loud noises, such as
rock concerts, that might cause temporary hearing loss. Temporary hearing
loss might cause unsafe volumes to sound normal.
• Do not listen at any volume that causes you discomfort. If you experience
ringing in your ears, hear muffled speech, or experience any temporary
hearing difficulty after listening to your portable audio device, discontinue
use and consult your doctor.
You can obtain additional information on this subject from the following sources:
186 Health and Safety