Velocity in Eigenfrequency Study

I trying to compute the eigenfrequecies and eigenmodes of a model. I have computed the Eigenfrequency study correctly. However, when I look at the generated values for the velocity (local RMS velocity, instantaneous, etc.) they are not what I am looking for and are all close to zero throughout the model. Is this because I am using the Sound Hard Boundary condition? Is the study even computing the velocity? Can I use another study or add another dependent variable that will actually calculate the velocity?

Thanks for any help