Samsung A640 - Manual (Page 252)

230 Section 4A: Important Safety Information
Getting the Best Hearing Device Experience With
Your Phone
To further minimize interference:
ⅷ There is usually less interference on the microphone setting than the
telecoil setting.
ⅷ Set the phone’s Display and Keypad backlight settings to ensure the
minimum time interval:
1.
Press Menu > Settings > Display > Backlight.
2.
Select Main Display or Keypad and press .
3.
Select the minimum time setting (8 seconds) and press .
ⅷ Use phones with a pull-out antenna. Phones with embedded
antennae may produce more interference.
ⅷ Position the phone so the antenna is farthest from your hearing aid.
ⅷ Move the phone around to find the point with least interference.