Zte Z610DL User Manual page 80

Setting Hearing Aids
Your phone supports HAC (Hearing Aid Compatibility)
function. If you use a hearing aid with a telecoil and turn on
hearing aid compatibility, it will help you hear more clearly
during phone calls.
1. Tap the Home Key > > > Settings >
Accessibility.
2. Check Hearing aids to turn on hearing aid compatibility.
CAUTION: Do not turn on the Hearing aids option unless you
use a hearing aid with a telecoil. Using this setting without a
hearing aid or with a hearing aid without a telecoil may be
harmful to your hearing.
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