Everything Revolves Around Sound

Artificial heads are indispensable for binaural sound recordings and measurements and for simulating speakers in communication device tests. However, there is a fundamental limitation: artificial heads are directionally static systems.

People turn their heads when listening and speaking, which produces several effects: On the one hand, listeners continuously perceive sound differently with head rotation as the ear sound reception changes. Put another way: We intuitively turn to better understand talkers by subconsciously ensuring that the critical frequency ranges for speech intelligibility arrive at our eardrums with higher signal energy and are not attenuated by the outer ear and our head.

The sound impression at the listener's ear also varies with a speaker's head movement. When a speaker turns their head, the oral sound field, i.e., the sound radiation coming from the mouth, changes significantly, especially in the area of the high-frequency sound components. Therefore, one turns just as intuitively toward the recipients for whom one wants to be as intelligible as possible as a talker.

In virtual and augmented reality, developers try to make the virtual world simulation more realistic by leaving the sound field in its natural position when the head is turned instead of letting it follow the rotation. This raises the question: Does the acoustic simulation still match the optical simulation during a head rotation?

Silent rotation for the perfect measurement

If these effects are ignored in measurements, the results do not reflect reality - and today's measurement technology does not consider them!

Therefore, HEAD acoustics has developed move°S. This base for artificial heads allows silent rotations of the mounted artificial head even during measurements, with comparable rotation angles as in humans (135 degrees per direction) and comparable speed from zero to 135 degrees in less than 1.5 seconds in "noiseless" operation.

This natural head rotation simulates real talkers and listeners and is a further step towards the simulation of lifelike human behavior in measurement technology - and thus towards better reproducibility, higher informative value for situations relevant to everyday life, and comparability of the measurements of different systems.

Best results for all applications

The move°S "shoulder" helps users to obtain more relevant results for measurements of all communication systems, especially for hands-free speech - also in vehicles -, for systems with directional behavior, for example, conference systems, and in the smart home, as well as for investigating the quality of virtual/augmented reality (VR/AR) communication systems. Investigating localization enhancement in binaural hearing due to head rotation becomes possible in the first place, as does investigating the head rotation compensation quality in VR/AR headsets. Tests of in-car communication (ICC) and speech recognition applications achieve significantly more precise and meaningful results with move°S measurements. In short, move°S is the all-around worry-free basis for realistic artificial head measurements whenever directional hearing and speech are involved.

In a nutshell, these are the main advantages of using the move°S platform
  • Virtually silent rotation - also possible during measurement
  • Natural head rotation: speed and rotation angle are comparable to the human head rotation
  • Simulation of a talker and a listener: Natural change of the mouth sound field and the ear sound reception
  • move°S is a further step towards the lifelike simulation of human behavior
  • High reproducibility of the motion sequence
  • Better comparability of measurement results

Upgrades for older systems, too

move°S is an optional upgrade for Generation 2021 HMS II.x and Generation 2021 HSU III.2, HSU III.3. HEAD acoustics Germany can also retrofit qualified HMS II.x and HSU III.2, HSU III.3 units already in your inventory with move°S technology.