An input device is provided that is configured to dynamically select and control y-scrolling and x-scrolling. As a solution, a baffle in size and shape is disposed about the flow-control member and adjacent facing surfaces bound therebetween a compartment of such nominal width that splashing does not occur therein. A key aspect of this device is the provision of air passages in the mounting insert which securely positions the hearing aid shell in the wearer’s canal. The nonmagnetic intermediate layer includes a thin film containing Ru. Running all threads of the additional instance of the application is continued.