Since both OC and TC fittings are appropriate for listeners with mild to moderately-severe hearing losses, evidence is needed to determine which style of hearing aid is preferred by a majority. Currently, OC fittings use a small behind-the-ear (BTE) hearing aid coupled to a thin tube or plastic covered wire ending in a vented "open" ear tip. When a TC fitting is used with patients with similar hearing losses, the majority are either an in-the-ear (ITE) or in-the-canal (ITC) .In the proposed study a comparison will be made between OC vs. TC fittings. In addition to this primary comparison, preference for one of two OC hearing aids, viz., OC instruments with receiver in the ear (OCRITE) and the OC instruments with receiver in the hearing-aid case (OCRIHA), will be determined. The outcomes of the OCRITE, OCRIHA, and TC hearing-aid use related to the factors of: (1) comfort and cosmetics, (2) subjective occlusion, (3) objective occlusion, (4) sound quality for external sounds, (5) feedback, (6) ease of use, (7) audibility, (8) aided signal-to-noise ratio (SNR) benefit, and (9) localization, will be measured in a large (n = 288), randomized-controlled, three-site (Bay Pines, Mountain Home, and Nashville) clinical trial, utilizing a three-period (two months each), cross-over design. A total of 13 variables will be measured for the 9 hearing-aid fitting and style-related factors. At the end of the study, participants will rank order their preferences for the three hearing aid fittings to determine (1) the preferred OC fitting (OCRITE vs. OCRIHA) and (2) whether the highest ranked OC fitting or the TC fitting is preferred. Preferred OC vs. TC difference scores will be calculated for all relevant variables. The ability of the differences scores to predict the preferences of the participants for an OC vs. TC hearing aid will be determined, in order to develop an evidence-based hearing aid selection model.