Samsung SEPM500BKASPR - Manual (Page 244)

220 Section 4A: Important Safety Information
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.)
The more immune your hearing aid device is, the less likely
you are to experience interference noise from your wireless
phone. Hearing aid devices 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:
ⅷ
Any combined rating equal to or greater than six offers
best use.
ⅷ
Any combined rating equal to five is considered normal
use.
ⅷ
Any combined rating equal to four is considered usable.
Thus, if you pair an M3 hearing aid with an M3 phone, you
will have a combined rating of six for "best use." This is
synonymous for T ratings.
Sprint Nextel further suggests you experiment with multiple
phones (even those not labeled M3/T3 or M4/T4) while in the
store to find the one that works best with your hearing aid
device. Should you experience interference or find the quality
of service unsatisfactory after purchasing your phone,
promptly return it to the store within 30 days of purchase.
With the Sprint 30-day Risk-Free Guarantee, you may return
the phone within 30 days of purchase for a full refund.