Sleep Sound Machine

FIG. 1 is a front, right and top perspective view of a sleep sound machine, showing my new design. FIG. 2 is a rear, left and bottom perspective view thereof. FIG. 3 is a front elevation view thereof. FIG. 4 is a rear elevation view thereof. FIG. 5 is a left side elevation view thereof. FIG. 6 is a right side elevation view thereof. FIG. 7 is a top plan view thereof. FIG. 8 is a bottom plan view thereof. FIG. 9 is an enlarged view of detail 9 in FIG. 1 ; and, FIG. 10 is another front, right and top perspective view of the sleep sound machine of FIG. 1 shown in an environment of use. The dashed broken lines depict portions of the sleep sound machine that form no part of the claimed design. The dot-dash broken lines in FIGS. 1 and 9 depict the boundaries of the enlarged views and form no part of the claimed design. The additional dashed broken lines in FIG. 10 depict environmental structure and form no part of the claimed design.