It appears that the ebuild for media-sounds/sndpeek is missing a dependency on libsndfile. I did not read the ebuild, but it failed on a linkage error becuase of missing libsndfile. Emerging libsndfile manually yielded a successful build.
Yep. Thanks. ssuominen@unique /tmp/sndpeek-1.3 $ grep -r "\-lsndfile" * src/sndpeek/makefile.osx-ub:#LIBS+= -lsndfile src/sndpeek/makefile.alsa:LIBS=-L/usr/X11R6/lib -lglut -lGL -lGLU -lasound -lXmu -lX11 -lXext -lXi -lm -lsndfile src/sndpeek/makefile.jack:LIBS=-L/usr/X11R6/lib -lpthread -lstdc++ -lglut -lGL -lGLU -lasound -ljack -lXmu -lX11 -lXext -lXi -lm -lsndfile src/sndpeek/makefile.oss:LIBS=-L/usr/X11R6/lib -lpthread -lstdc++ -lglut -lGL -lGLU -lXmu -lX11 -lXext -lXi -lm -lsndfile