The analysis of ultrasonic vocalizations

Although rats do make audible sounds, most communication, particularly between rats takes places at a frequency beyond our human hearing. These so-called ultrasonic vocalizations (USVs) in rats range from roughly 22 to 90 kHz. Traditionally, USV research has shown that rat calls in the 20 – 25 kHz range are typically associated with negative affect, while calls in the 40 – 90 kHz range are typically associated with positive affect. Rat pups, when separated from their mothers usually make calls in the 30 – 45 kHz range. While this subdivision in three… Read More