R help - Mar 2010 - Two-way multivariate analysis of variance (single group of subjects)

Hello,

I have ratings of a single group (10 subjects) for 16 audio samples on a
semantic differential with 14 items. The audio samples are varied by two
factors: circuit and content - each with 4 levels.

I want to do an exploratory analysis of variance to find out if there
are different mean ratings due to the circuit, content and interaction
of circuit and content.

For single items I did an univariate analysis of variance with

anova.x <- ezANOVA(x, Item[n], .(Subject), within = .(Circuit, Content))

from the ez package.

How could I do a multivariate analysis of variance for this design?

Thanks in advance,
Tobias