Zte Z557 User Manual page 78

Accessibility.
2. Turn on 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.
Check About Information
You can check the build version of the Phone app, open source
licenses, privacy policy, and terms of service. Touch the Home
key > > > Settings > About.
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