Balanced Armature drivers for hearing health applications are sometimes measured using an ITE 10-by-1 2cc coupler. It provides a reasonable simulation of the ear’s response through the first peak, up to about 4 kHz. If a Balanced Armature driver measured in this way is intended to be used as a woofer or woofer-midrange, a good idea of the response in an earphone can be inferred. Note that while the response shape is about the same as with the 711 coupler, the level is different due to the different air volume in the coupler.