Hearing is such a normal experience for most of us that we hardly notice it. Imagine the following situation: You are sitting on a bus surrounded by the background noise of the rhythmic rumbling of the bus. Here and there snippets of talk can be heard. A child is spontaneously singing a description of what she sees outside the window until the mother asks her to sing more softly. Elsewhere, two adolescents are exchanging informed opinions on the latest music, throwing in names and terms that ordinary musicologists or music educators do not even understand. In the back, a businessman is talking on the phone to an invisible but certainly highly valued costumer, using a servile tone and frequent jovial laughs. Having planned that the bus ride would be a great time to get some serious work done, you try to focus on the reading material—in vain. Even after mumbling the text to yourself, you still cannot concentrate. Finally, you put in your ear plugs. Seconds later the ambient noises have been reduced to a muffled minimum, and you can start reading.
This scene reveals that our auditory system is continuously receiving information and, unlike the eye, cannot be closed off to the environment. Although a multitude of sounds (even noxious ones) are present at one time and compete for our attention, we allocate our attention selectively and evaluate what we hear. The linguistic difference between hearing (perceiving sound) and listening (paying attention to sound) exists in many languages. Although the details of sound perception lie beyond the scope of this book, we later describe the path of acoustical stimuli from where they emanate to where they are processed in our brains. Although all people of normal hearing can perceive sounds, listening requires active attending to information. Even deaf people can hear extremely loud or low-frequency information through their bodies. When we talk about listening, we mean the conscious attention to some sound source as opposed to the passive intake of background music in stores, ambient noises, or