  Alfv\'enic waves are thought to play an important role in coronal heating and
acceleration of solar wind. Here we investigated the statistical properties of
Alfv\'enic waves along spicules (jets that protrude into the corona) in a polar
coronal hole using high cadence observations of the Solar Optical Telescope
(SOT) onboard \emph{Hinode}. We developed a technique for the automated
detection of spicules and high-frequency waves. We detected 89 spicules, and
found: (1) a mix of upward propagating, downward propagating, as well as
standing waves (occurrence rates of 59%, 21%, and 20%, respectively). (2) The
phase speed gradually increases with height. (3) Upward waves dominant at lower
altitudes, standing waves at higher altitudes. (4) Standing waves dominant in
the early and late phases of each spicule, while upward waves were dominant in
the middle phase. (5) In some spicules, we find waves propagating upward (from
the bottom) and downward (from the top) to form a standing wave in the middle
of the spicule. (6) The medians of the amplitude, period, and velocity
amplitude were 55 km, 45 s, and 7.4 km s$^{-1}$, respectively. We speculate
that upward propagating waves are produced near the solar surface (below the
spicule) and downward propagating waves are caused by reflection of (initially)
upward propagating waves off the transition region at the spicule top. The mix
of upward and downward propagating waves implies that exploiting these waves to
perform seismology of the spicular environment requires careful analysis and
may be problematic.
