TOEFL Listening

🎧 Listening Transcript

Listen to part of a lecture in a biology class. The professor is discussing animal communication. 'Today, we're going to talk about a fascinating aspect of animal behavior: communication. While many animals use sounds, visual signals, or chemicals called pheromones, some species have developed surprisingly complex systems. Take the honeybee, for example. When a forager finds a rich source of nectar, it returns to the hive and performs what is called a 'waggle dance.' This dance conveys the direction and distance of the food source relative to the sun. The angle of the dance in relation to the vertical hive surface indicates the direction, and the duration of the waggle run signals the distance. This is an abstract form of communication because the bee is representing something that is not immediately present. In contrast, consider the alarm calls of vervet monkeys. These monkeys have distinct calls for different predators—leopards, snakes, and eagles—and each call triggers a specific escape response. This shows a level of semantic meaning. However, unlike human language, these systems lack productivity; that is, they cannot combine signals to create new meanings. So, while animal communication can be complex, it remains fundamentally different from human language.'