Information updated as of June 2014
Yealink
Some Yealink products are listed in their datasheets as Hearing Aid Compatible, and others not, but having discussed this with their UK technical staff, we understand that the T41PN, T42GN, T46GN and T48GN models are fitted with a ‘T’ mode inductive loop in the handset.
snom
Our supplier has informed us that none of the current snom handsets have support for hearing aids. The snom m3 DECT did but it is now a discontinued product.
Polycom
From the Polycom datasheets on the IP and VVX range handsets:
“All Polycom handsets are Hearing Aid Compatible (HAC) and have telecoils that magnetically couple to most forms of wearable hearing aids per FCC section 508 (compliant to ADA Section 508 Recommendations: Subpart B 1194.23).”