Palm Centro User Manual page 129

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 those of phones. Ask your hearing health-care 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 best use.
Any combined rating equal to five is considered normal use.
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.
Palm further suggests that 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. If you experience interference or find the quality of service unsatisfactory after
purchasing your device, promptly return it to the store within 30 days of purchase. With the
Palm 30-day Risk-Free Guarantee, you may return the device within 30 days of purchase for
a full refund, and you will only be responsible for charges based on your actual usage.
Getting the Best Hearing Device Experience With Your Device
To further minimize interference:
There is usually less interference on the microphone setting than on the telecoil setting.
Set the phone's screen and keyboard backlight settings to ensure the minimum time
interval.
Move the phone around to find the point with the least interference.
If your hearing aid is equipped with a telecoil, turn on the HAC setting on your device.
Safety 123