Motorola I290 - Manual (Page 96)

90 Safety Information
• Any combined rating equal to four is considered usable.
Thus, if you use an M3 phone with a M3 hearing aid you will have
a combined rating of six for “excellent use.” This methodology
applies equally for T ratings.
More information about hearing aid compatibility may be found at:
www.motorola.com/accessibility, www.fcc.gov, www.fda.gov, and
www.hearingloss.org/learn/cellphonetech.asp