Kyocera DuraForce Quick Start Manual page 26

These ratings are not guarantees. Results will vary
depending on the user's hearing device and individual type
and degree of hearing loss. If a hearing device is particularly
vulnerable to interference noise; even a phone with a higher
rating may still cause unacceptable noise levels in the
hearing device. Trying out the phone with your hearing
device is the best way to evaluate it for your personal needs.
M-Ratings: Phones rated M3 or M4 meet FCC requirements
for hearing aid compatibility and are likely to generate less
interference to hearing devices than unrated phones. (M4 is
the better/higher of the two ratings.)
T-Ratings: Phones rated T3 or T4 meet FCC requirements
and are likely to be more usable with a hearing device's
telecoil ("T Switch" or "Telephone Switch") than unrated
phones. (T4 is the better/higher of the two ratings. Note that
not all hearing devices have telecoils in them.)
Note: This phone has been tested and rated for use with
hearing aids for some of the wireless technologies
that it uses. However, there may be some newer wireless
technologies used in this phone that have not been
tested yet for use with hearing aids. It is important to
try the different features of this phone thoroughly
and in different locations, using your hearing aid or
cochlear implant, to determine if you hear any
interfering noise. Consult your service provider or the
manufacturer of this phone for information on
hearing aid compatibility. If you have questions about
return or exchange policies, consult your service
provider or phone retailer.
Hearing aid devices may also be measured for immunity to
interference noise from wireless phones and should have
ratings similar to phones. Ask your hearing healthcare
professional for the rating of your hearing aid. Add the rating
of your hearing aid and your phone to determine probable
usability:
● Any combined rating equal to or greater than six offers
excellent use.
Important Safety Information 26