Although tigers are generally solitary animals, acoustic communication among conspecifics plays an important role in their biology and behavior. This investigation was undertaken to extend understanding of prusten, one of the most common vocalizations produced by Panthera tigris. Prusten is a low-level, social vocalization uttered in close proximity of conspecifics. Calls were recorded from a group of nine captive adult tigers, representing the Amur (P. tigris altaica), Bengal (P. tigris tigris) and Malayan subspecies (P. tigris jacksoni). As described previously, the acoustic character of prusten consists of three to nine brief rhythmic pulses emitted at a mean rate of 11.5 pulses per second with a total mean duration of 0.5 seconds. Calls were generally low level, with a mean of 71 dB SPL re 20 μPa at 1 meter from the source. Spectral energy was broadband, extending from below 20 Hz to above 22 kHz, although low frequency energy dominated the call with mean peak and centroid frequencies of 130 and 987 Hz, respectively. A small subset of calls contained infrasonic energy. This study affirms and extends findings from previously published descriptions and is the first report of the production of infrasound in this low level, pulsatile vocalization. [Work supported in part by NSF Grant Award #0823417.]