Improving elevation perception with a tool for image-guided head-related transfer function selection

This paper proposes an image-guided HRTF selection procedure that exploits the relation between features of the pinna shape and HRTF notches. Using a 2D image of a subject's pinna, the procedure selects from a database the HRTF set that best fits the anthropometry of that subject. The proposed procedure is designed to be quickly applied and easy to use for a user without previous knowledge on binaural audio technologies. The entire process is evaluated by means of an auditory model for sound localization in the mid-sagittal plane available from previous literature. Using virtual subjects from a HRTF database, a virtual experiment is implemented to assess the vertical localization performance of the database subjects when they are provided with HRTF sets selected by the proposed procedure. Results report a statistically significant improvement in predictions of localization performance for selected HRTFs compared to KEMAR HRTF which is a commercial standard in many binaural audio solutions; moreover, the proposed analysis provides useful indications to refine the perceptually-motivated metrics that guides the selection

Volatile and phenolic composition of monovarietal red wines of Valpolicella appellations

The volatile and phenolic compositions of nine monovarietal wines from the following grape varieties allowed in the Valpolicella appellation were investigated: Corvina, Corvinone, Rondinella, Molinara, Oseleta, Raboso, Croatina, Sangiovese and Cabernet-Sauvignon. Different clones were also investigated for Corvina and Corvinone, the two main varieties of the appellation. All grapes were harvested from a single experimental block and vinified following a standard protocol. Wines from different clones of Corvina were characterised by higher monoterpenols content, including linalool, \u3b1-terpineol and geraniol, as well as by a peculiar pattern of C6-alcohols. Relatively high levels of monoterpene alcohols were also found in Corvinone wines, while Oseleta showed the highest concentration of terpinen-4-ol and cis- and trans- isomers of linalool oxide. The evaluation of the wine aroma profile by means of different aromatic series indicated higher values for the \u201cfloral\u201d, \u201cfruity\u201d and \u201cripe fruit\u201d series for Corvina and Corvinone wines. Major differences in phenolic composition were found between the different varieties of wine. The total phenolics and total tannins values for Corvina, Corvinone, Rondinella and Molinara wines indicated relatively low phenolic content in comparison with Croatina, Oseleta, Cabernet-Sauvignon. There were also major differences in the content of individual phenolic compounds, in particular anthocyanins, between the monovarietal wines