  Non-commutative geometry at inflation can give arise to parity violating
modulations of the primordial power spectrum. We develop the statistical tools
needed for investigating whether these modulations are evident in the Cosmic
Microwave Background (CMB). The free parameters of the models are two
directional parameters (theta,phi), the signal amplitude A*, and a tilt
parameter n* that modulates correlation power on different scales. The
signature of the model corresponds to a kind of hemispherical power asymmetry.
When analyzing the 7-year WMAP data we find a weak signature for a preferred
direction in the Q-, V-, and W bands with direction (l,b) = (-225 deg,-25 deg)
+- (20 deg, 20 deg), which is close to another previously discovered
hemispherical power asymmetry. Although these results are intriguing, the
significance of the detection in the W-, V- and Q-bands are nonzero at about 2
sigma, suggesting that the simplest parameterization of the leading correction
represents only partially the effects of the space-time non-commutativity
possibly responsible for the hemispherical asymmetry. Our constraints on the
presence of a dipole are independent of its physical origin and prefer a
blue-tilted spectral index n* ~ 0 with the amplitude A* ~ 0.18.
