At a short track just three or four drivers will keep your ears busy while at a superspeedway you can listen to seven or eight drivers without being overwhelmed. The shorter the race track the greater the amount of information that the spotter and the crew chief need to exchange with their driver.
What Can You Hear?
The most common phrase heard over the scanner is "clear." The spotter says this to tell the driver that there is no longer a car beside him and that he can move back up (or down) into the groove after a pass.
After the driver has a few laps on the tires he will usually report in on how the car is handling. This usually consists of the driver saying that the car is loose or tight and in what part of the turn (entering, the center or exiting) followed by a short discussion about how to fix it (track bar, wedge, air pressure, etc...)
You will also hear strategy discussions such as when to pit, who to pit with, who to draft with, when to lay back and when to press hard. Since the driver is concentrating on driving the car it can be helpful for his crew chief to fill him in on the bigger picture of what is going on in the race.
Also, many people spend a significant amount of time listening to the MRN broadcast of the race. This can be helpful to get you straightened out as to what's going on or who is still on the lead lap over the course of a long green flag run when they get spread out. Another good use of the MRN broadcast is to find something interesting on the race track during a boring stretch of the race. The MRN guys always are talking about the most exciting thing going on, if you can't find the battle yourself drop by the broadcast and see what they are talking about.