The acceleration of ionospheric ions transverse to the geomagnetic field by factors of 103 is believed to be caused by plasma waves. We have made simultaneous measurements of electric fields (0--16kHz) and energetic ions (50eV to 20keV) within regions of perpendicular ion acceleration ion acceleration from the sounding rocket MARIE. Perpendicular ion acceleration was correlated with plasma waves near and above the lower hybrid frequency. Ions were detected up to energies of 300 eV and the broadband lower hybrid waves reached an amplitude of 10--30 mV/m (RMS) over the frequency band 4--16 kHz. Although electric field amplitudes near the 0+ cyclotron frequency reached a maximum value of 10 mV/m (RMS), there was no spectral evidence of electrostatic ion cyclotron waves associated with ion acceleration. There was spectral evidence of H+ Bernstein modes near the lower hybrid frequency. If we assume that whistler mode waves near and above the lower hybrid frequency were responsible for the ion acceleration then the conversion efficiency of wave energy to ion energy was .01 to .1.