We report that the electroreceptors in paddlefish possess the novel property of being biperiodic, that is, being composed of two intrinsic self-sustained noisy oscillators, one residing in the hair cells, and another in the terminals of primary afferent neurons. The two oscillators are coupled unidirectionally. Thus the receptor system as a whole undergoes stochastic biperiodic oscillations. We characterize the spontaneous activity of this system of coupled biological oscillators, and also discuss the impact of the biperiodic organization on the transduction of external sensory stimuli. In particular, we show that the existence of hair cell oscillations leads to additional variability of afferent spike trains.