Vibro-Acoustical Beats: Inducing Auditory Perception Through Whole-Body Vibration

"en-US">People experience whole-body vibration (WBV) in many situations in daily life. Most of the time the vibrations occur simultaneously with acoustical signals, as both vibration and sound stem from the same source. This leads to multi-modal effects between WBV and sound that can be exploited for the design of multi-modal virtual environments and effect the overall perception of, for example, comfort in multi-modal situations such as riding a car or attending a concert. It has been speculated that low level WBV lead to auditory cues which might influence the outcome of vibration experiments. This study uses an indirect approach to prove this hypothesis. The concept of binaural beats is broadend to vibro-acoustical beats. The simultaneous presentation of two sinusoidal signals with a few Hertz difference between headphones and whole-body vibration leads to the auditory perception of beats. This was tested with two different sound levels across five different frequency from 31.5 to 125 Hz. By comparing the results of the vibro-acoustical beats with purely acoustically generated beats, it can be concluded that clearly perceivable vibrations approximately 10 to 15 dB above perception threshold lead to faint sound impressions approximately 17 to 20 dB less than the acoustical reference.