I claim the ornamental design for a hearing assistance device, as shown and described.
FIG. 1 is a perspective view of a hearing assistance device of the present invention,
FIG. 2 is a front elevation view of the hearing assistance device of FIG. 1;
FIG. 3 is a back elevation view of the hearing assistance device of FIG. 1;
FIG. 4 is a left side elevation view of the hearing assistance device of FIG. 1;
FIG. 5 is a right side elevation view of the hearing assistance device of FIG. 1;
FIG. 6 is a top plan view of the hearing assistance device of FIG. 1; and,
FIG. 7 is a bottom plan view of the hearing assistance device of FIG. 1.
The broken lines in FIGS. 2–6 are included for the purpose of illustrating portions of the hearing assistance device that form no part of the claimed design.