These two tracks entrain the brain to specific frequencies in the lower regions of Beta brainwaves, beneath 20 Hertz. Most people are operating in a stressful brainwave frequency above 20Hz during their days, so listening to these tracks while you work, commute, run errands or anything else during your waking day will help you maintain a calm, yet active state of mind.
All techniques, whether mantra, focus on the breath, contemplation of a koan, or any other, are simply the vehicles we use to take us into (hopefully) a meditative state. Put another way, the purpose of repeating a mantra is not to get proficient at repeating a mantra. The purpose is to take us to a meditative state where the mantra slips away and is no longer necessary.
The activity of neurons generate electric currents; and the synchronous action of neural ensembles in the cerebral cortex, comprising large numbers of neurons, produce macroscopic oscillations. These phenomena can be monitored and graphically documented by an electroencephalogram (EEG). The electroencephalographic representations of those oscillations are typically denoted by the term 'brainwaves' in common parlance.