Linda, Advanced Bionics uses a 49.1 mHz uplink and a 106.6 downlink for their
units. The uplink could be causing you a third harmonic problem although it
really shouldn't.
To check this the easy way, you'll either need a hearing person or you'll have
to have some hearing with your implants shut down. Set your ht for maximum
problem and shut down your implants. If the noise in your receiver stops you've
probably found the problem and you'll then need to be checking for a shielding
issue if the problems happen at a distance of more than a few feet from your
implants.
Tom
Tom Brennan KD5VIJ, CCC-A/SLP
web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html