Anthropometric contribution to standardising manikins for artificial-head microphones and to measuring headphones and ear protectors.

True-to-size head-torso manikins are required for research in the field of artificial-head stereophony as well as for testing and measuring headphones, soundproof helmets, ear protectors and other headgear. Attempts to design a manikin according to the available anthropometric data available proved to be difficult. By testing 77 men with technical jobs, 15 new quantities have been measured, some of them for comparison and some to complete existing measurements.

Fluorescent tube light evokes flicker responses in visual neurons.

Single neurons in the cat visual system respond distinctly to the temporal information present in light from fluorescent tubes driven by 50 or 60 Hz alternating current. Despite the resulting flicker frequencies of 100 or 120 Hz all retinal and most thalamic neurons show strong phase locking of the neuronal responses to the modulation of fluorescent tube light. Some retinal ganglion cells have not yet reached their critical flicker fusion frequency under such conditions.