Effect of psychological stress on female vocal quality. A multiparameter approach.

Psychological stress can influence vocal quality. The purpose of the present study was to determine the effect of stress on female vocal quality. In this experimental study 54 female voices were studied in a stress-inducing and a relaxed condition. In the stress-inducing condition the subjects were asked to read a passage while instructions were used to evoke stress. In the relaxed condition the same reading task but without specific instructions was used. Identical subjective and objective assessment techniques were used to determine vocal quality in the stressed and the relaxed conditions. In stress-inducing and challenging conditions the female voice is more breathy, strained and of a lower objective vocal quality characterized by lower fundamental frequency, lower frequency, intensity and aerodynamic capacity. This study indicates that stress-inducing and challenging conditions change vocal quality and vocal performance. Understanding of the effect of stress on voice production is relevant for clinical diagnostic situations, particularly in patients who present with a functional (nonorganic) voice disorder, as well as those patients who have some organic pathology but who also report exacerbation of symptoms during periods of increased life stress.

Cold neutron energy dependent production of ultracold neutrons in solid deuterium.

A measurement of the production of ultracold neutrons from velocity-selected cold neutrons on gaseous and solid deuterium targets is reported. The expected energy dependence for two-particle collisions with well defined neutron and Maxwell-Boltzmann distributed molecular velocities is found for the gas target. The solid target data agree in shape with the phonon density-of-states curve and provide strong evidence for the phonon model including multiphonon excitations.

Direct experimental limit on neutron-mirror-neutron oscillations.

In case a mirror world with a copy of our ordinary particle spectrum would exist, the neutron n and its degenerate partner, the mirror neutron n', could potentially mix and undergo nn' oscillations. The interaction of an ordinary magnetic field with the ordinary neutron would lift the degeneracy between the mirror partners, diminish the n' amplitude in the n wave function and, thus, suppress its observability. We report an experimental comparison of ultracold neutron storage in a trap with and without superimposed magnetic field. No influence of the magnetic field is found and, assuming negligible mirror magnetic fields, a limit on the oscillation time taunn' > 103 s (95% C.L.) is derived.

Measured total cross sections of slow neutrons scattered by solid deuterium and implications for ultracold neutron sources.

The total scattering cross sections for slow neutrons with energies in the range 100 neV to 3 meV for solid ortho-2H2 at 18 and 5 K, frozen from the liquid, have been measured. The 18 K cross sections are found to be in excellent agreement with theoretical expectations and for ultracold neutrons dominated by thermal up scattering. At 5 K the total scattering cross sections are found to be dominated by the crystal defects originating in temperature induced stress but not deteriorated by temperature cycles between 5 and 10 K.