ABSTRACT
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. The tests showed that it is absolutely essential to differentiate manikins of the desired qualities from an ethnic point of view. Manikins of different model dimensions should not be standardised according to percentiles but should represent typical head shapes. To this end, thorough measurements have to be made.
ABSTRACT
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. Though usually beyond perception, the frequency and depth of modulation of artificial light thus might well play a role in biological light effects.
