Localized packets of electrostatic whistler emissions near the lower hybrid frequency have been observed in the low-attitude auroral region by sounding rockets and the Freja satellite. We present a model for wave localization that requires two ion species, O+ and H+, whereby the minority H+ ions control the localization process. The theoretical basis is that the plasma dispersion is dramatically affected by small changes in the H+ density and that the observed emissions would selectively heat H+. We show observational support for the proposed model. ¿ American Geophysical Union 1995