6 March 2013 by Permi Krishna
Most of the cellphones operate in frequencies which interfere with hearing-aid devices. Consequently, FCC has defined a Hearing Aid Compatibility (HAC) standard for cellphones, which helps in figuring out the best cellphones for least interference with hearing aids.
The HAC standard defines two radio-frequency emission rating: The "M" rating and the "T" rating. The "M" rating corresponds to interference with the hearing aid in the microphone mode, and the "T" rating corresponds to interference with the hearing aid in t-coil mode.
Both M and T values range from 1 to 4, with 1 being the highest emission/interference and 4 being the least emission/interference. Consequently, the phones with the highest M and T values (M4/T4) provide the least interference with hearing aids.
This reviewgist list for the best cellphones for the hearing impaired takes into account the M and T ratings and we list only cellphones which have ratings from either of M3, M4, M3/T3, M3/T4, M4/T3 or M4/T4.