Unlike older generation whose consumption of music was bounded by their local culture, today’s young consumers access music beyond cultural boundaries. Many successful pop music in cyber space attracted billions of listeners from all over the world. The young generation born and raised in the digital age, are often thought to have altered sensory-neural characteristics because of their extensive use of electronic device since early childhood. This study investigates a perceptual saturation hypothesis which posits that in order to capture the young generation’s hard-to-get attention, online music must present a high level of energy and rhythm that is near the point of perceptual saturation. We conducted a functional near-infrared spectroscopy (fNIRS) experiment with sixty-four young adults and found that total cerebral blood volume over prefrontal brain area was higher for a song that presents acoustic intensity near the point of perceptual saturation than a counterpart stimulus with lower levels of acoustic intensity. The degrees of prefrontal hemodynamic randomness decreased significantly while the participants listened to YouTube music that provided high levels of acoustic stimulation. Online popularity, recorded as the number of daily hits, was positively correlated with the total cerebral blood volume and negatively correlated with hemodynamic randomness.