When rock concerts and dance halls have played rock music at high
intensities (painfully to many) for more than 50 years, it cannot
be just a 'cultural artifact'. When the volume is below about
95dB, complaints occur that the music is not loud enough. Repeated
behavior is the definition of a rewarded behavior, therefore there
is an obvious pleasure of a very loud rock beat. As shown by Todd
and Cody (Todd2000), at about 95dB, the bass beat will 'leak' some
of the pressure wave from the cochlea to a vestibular otolith organ.
That pressure wave thus provides a nice vestibular impulse that is
perfectly timed with the auditory beat. |
While Todd and Cody thought that the pleasure is only from the vestibular stimulation, they did not consider that the pleasure is from an in-phase, rhythmic co-stimulation of an auditory beat with a vestibular impulse. This simultaneous stimulation of auditory beat and vestibular impulse also occurs with dance. During dance, head nodding is not smooth but jerks back on the beat which is a vestibular jerk (an impulse). Also in dance, foot striking occurring on the beat causes a shockwave impulse through the skeleton to the head; that shockwave is felt as a vestibular impulse. Dance music has a very strong beat (usually a bass drum); therefore, for dancing, the auditory beat and the vestibular impulse are also in-phase and rhythmic.
Dancing is pleasurable (by the definition of rewarded behavior as repeated behavior), and that pleasure is likely from multiple sources. However, since dancing is very pleasurable (at least dancing where you stay in time to the beat) and the rock-and-roll threshold implies pleasure, it is reasonable to suspect some common pleasure driving them. The strong candidate for a common pleasure would be: an in-phase, rhythmic co-stimulation of an auditory beat with a vestibular impulse.
Why would that particular sensory stimulation be pleasurable in humans? Oddly, it does seem unique to humans and some birds. At a presentation at a music conference, I dubbed this pleasure sensation, RAVI -- Rhythmic Auditory Vestibular Impulse. Interestingly, if this pleasure from RAVI exists, many complex human unique results are expected (because a pleasure repeatably motivates all behaviors that produce the pleasure). All the expected behaviors do occur in humans (and are absent from non-human primates), thus lending support for the existence of RAVI pleasure in humans.
So back to the rock concerts as hearing damaging: unfortunately, they are likely going to stay that way. But if it is RAVI pleasure as the driving force behind the rock-and-roll threshold, we can simulate the pressure wave 'leak' of the inner-ear . We just need to make a headband device that delivers a vestibular impulse (a small hammer perhaps) which is in-phase with the auditory beat. With that device, the volume can be turned down to perhaps only ten. Maybe the device can be a GoogleGlass accessory so it can be accepted? I don't see it becoming popular.
-- a former RAVI enthusiast who would like his hearing fully back
See http://www.nature.com/news/2000/000107/full/news000113-2.html for Philip Ball's view.
Todd, N.P. & Cody, F.W. Vestibular responses to loud dance music: A physiological basis of the "rock and roll threshold"? JASA 107, 496 - 500 2000.