ZTE ZMAX - Manual (Page 161)

159
Radio Frequency Interference
General Statement on Interference
Care must be taken when using the phone in close proximity to personal
medical devices, such as pacemakers and hearing aids.
Pacemakers
Pacemaker manufacturers recommend that a minimum separation of 15
cm be maintained between a mobile phone and a pacemaker to avoid
potential interference with the pacemaker. To achieve this, use the phone
on the opposite ear to your pacemaker and do not carry it in a breast
pocket.
Hearing Aids
People with hearing aids or other cochlear implants may experience
interfering noises when using wireless devices or when one is nearby.
The level of interference will depend on the type of hearing device and
the distance from the interference source. Increasing the separation
between them may reduce the interference. You may also consult your
hearing aid manufacturer to discuss alternatives.