The transfer functions between acceleration and force (‘‘accelerance’’) at the driving point and radiation efficiencies for the top plates of guitars have been investigated. A vibration exciter was used for driving the guitar at the bridge and the transfer functions and cross‐power spectra were measured at the driving point with the aid of an impedance head. The frequency spectrum of the accelerance function determined in this manner showed good agreement with those reported for the same guitar using a different excitation and measurement method. The output acoustic intensity was measured with a sound‐intensity probe and the radiated sound power from the top plate was determined. The radiation efficiency, determined from the ratio of the top plate radiated sound power and the input power, is presented for different guitars and for a guitar with a modified top plate.