February 18, 2019. by Douglas L. Beck. The improvements in SNR are dramatic and easily on the order of 20-25 dB, as with those documented in personal FM system studies.1 Occluding earmolds may increase the SNR if the instrument is set to T-only, while open-canal instruments reduce those numbers. In hearing loops installed to the IEC standard, the hearing can be exquisite. I have personally used hearing aids in hundreds of loops; perhaps it’s due to my Dutch brain, but I just love how I can just sit back and hear with ease, while using a loop. Hearing loops decrease cognitive load. A survey I completed among some 327 loop users at an HLAA convention showed that listening effort changed dramatically—on a scale from 1 to 10, it fell from an average of 6.9 out of the loop to 1.9 in the loop.
