This paper presents a description of the APEX speech production model and some of its main current capabilities. We describe an ongoing X-ray project initiated to calibrate APEX according to individual speaker characteristics and to obtain data on how articulatory movements are coordinated in the coarticulation of Swedish vowels and stops. The mapping of the X-ray data onto APEX parameters is a...

The duplex theory postulates that low-frequency tones are localized on the basis of interaural time differences (ITDs) while tones above 1.5 kHz are localized by evaluating interaural level differences (ILDs) [1]. Recent research showed that ITDs are also dominant for wide-band sounds [2]. The contribution of envelope-ITDs is supposedly small, but enhanced by temporal modulation [3]. Using tone...

The way in which color signals from the three cone classes (L, M, S) are handled by the rest of the visual system to bring about color perception is incompletely known. In particular, the neural mechanism underlying two fundamental features of color vision, color contrast and color constancy, are unclear. Modeling efforts have shown that these features could be accounted for by neurons capable ...

Understanding how the brain extracts the behavioral meaning carried by specific vocalization types that can be emitted by various vocalizers and in different conditions is a central question in auditory research. This semantic categorization is a fundamental process required for acoustic communication and presupposes discriminative and invariance properties of the auditory system for conspecifi...

The entropy budget of an atmosphere in radiativeonve tive equilibrium is analyzed here. The di erential heating of the atmosphere, resulting from surfa e heat uxes and tropospheri radiative ooling, orresponds to a net entropy sink. In statisti al equilibrium, this entropy sink is balan ed by the entropy produ tion due to various irreversible pro esses su h as fri tional dissipation, di usion of...