A bobcat's sound is generally that of a low-pitched guttural growl. The sound is surprisingly lower in pitch and longer in length than you might expect. Not as deep as say a lion or tiger, because they are not as large of animals therefore do not have the same resonance.
Bobcats sound very similar to a common house cat. There sounds vary depending on the time of year, they sort of howl when its close to mating season to attract a mate. They will also hiss and meow like a house cat to express itself. THough for the most part bobcats are quiet when it is not mating season
A bobcat sounds somewhat like a mountain lion except that it is more high pitched and shorter. Bobcats do make a variety of sounds, but you could be hearing their defensive/offensive meow or roar (which ever you prefer).