Recently, the open canal (OC) hearing-aid style has become a viable approach to addressing address many of the problems resulting in non-use of traditional hearing aids, particularly for individuals with mild to moderately-severe hearing loss. Although an OC hearing aid has many potential advantages, there also are potential limitations. For example, the maximum low and high-frequency gain available with an OC fitting is less than that available from traditional custom (TC) hearing-aid fittings, which could result in less than optimal amplification for some individuals. In addition, directional microphone benefits for speech understanding in noise, available with TC fittings, likely will be limited with OC fittings due to the loss of low-frequency gain (Ricketts et al., 2005).