Look out for low-frequency vehicle noise
If you often become tired when you are driving, the culprit may be noise, and in many cases, “audible” noise may be the most dangerous. The acoustic environment inside a car is often dominated by extremely low-frequency noise, and Truls Gjestland, a senior scientist at SINTEF, says that such sounds can be tiring. Even sounds made up of frequencies that are so low that they are not perceived directly by our ears (so-called “infrasound”) also tend to make us drowsy.