The ornamental design for a hearing implant accessory, as shown and described.
FIG. 1 is a rear, left perspective view of a hearing implant accessory showing our new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a rear, left perspective view of the design in a position of use.
The dash-dot-dash lines represent the bounds of the claim, the broken lines showing a human head in FIG. 8 representing the environment in which the design may reside, and the other broken lines show a portion of the hearing implant accessory that forms no part of the claimed design.