Aspects of the subject technology relate to electronic devices having speakers. An electronic device may operate the speaker at or near one or more resonance frequencies of the speaker and/or the electronic device. This can allow the electronic device to efficiently eject an occlusion when the speaker is occluded by a fluid or other debris. For example, the electronic device may determine a resonance frequency by obtaining one or more electrical characteristics of an electronic component while the speaker is occluded, determine the resonance frequency based on the obtained electrical characteristic(s), and operate the speaker at a frequency that is based on the resonance frequency to eject the occlusion.