Abstract: A portable instrument for phonocephalography is provided having a pair of ear insertable microphones of sufficient sensitivity to detect sounds from the surface and cavities of the head. An amplifier is provided for increasing the output signal from each microphone. The amplified signals from each microphone are passed through a frequency analyzer and a multiplexing oscillator for display on a two channel oscilloscope. Alternatively or additionally, the amplified signals may be displayed on a chart recorder. An ECG pickup and amplifier may additionally be provided, having input to the second channel oscilloscope, for correlating ECG signals with sounds from the ear. Such a device may be portable and provides a simple, passive, non-invasive technique for diagnosis of, for example, tinnitus and intratemporal carotid aneurysm, and permits correlation of audible sounds from the head with a patient's ECG.