Volume 121, Issue 4, April 2007
Index of content:
- MUSIC AND MUSICAL INSTRUMENTS 
121(2007); http://dx.doi.org/10.1121/1.2697059View Description Hide Description
This study investigates the discrimination of small changes of interval size in short sequences of musical tones. Major, minor and neutral thirds were varied in increments of . The nine subjects had varying degrees of amateur musical experience—their level of musical training was lower than that of professional musicians. In some experiments the stimuli were presented purely melodically and in others they were presented together with a sustained tone at a higher pitch. Some subjects were able to make use of the additional cues from beats in the latter case. Category widths for identification were measured at around and just-noticeable differences in frequency were measured at around . Little significant variation of inter-stimulus sensitivity index was observed across the stimulus sets, i.e., there was little evidence for “anchors” or “landmarks” within the range of tunings employed. However, for major thirds, discrimination of the increment between 400 and was reduced compared to discrimination of other increments within the stimulus sets.
Resonance wood [Picea abies (L.) Karst.] – evaluation and prediction of violin makers’ quality-grading121(2007); http://dx.doi.org/10.1121/1.2434756View Description Hide Description
The definition of quality in the field of resonance wood for musical instrument making has attracted considerable interest over decades but has remained incomplete. The current work compares the traditional knowledge and practical experience of violin makers with a material-science approach to objectively characterize the properties of resonance wood. Norway spruce [Picea abies (L.) Karst.] has earned a very high reputation for the construction of resonance tops of stringed instruments and resonance boards of keyboard instruments, and was therefore chosen as the focus of the investigation. The samples were obtained from numerous renowned resonance wood regions in the European Alps and cover the whole range of available qualities. A set of acoustical, anatomical, mechanical and optical materialproperties was measured on each sample. These measurements were compared with subjective quality grading by violin makers, who estimated the acoustical, optical and overall suitability for violin making. Multiple linear regressionmodels were applied to evaluate the predictability of the subjective grading using the measuredmaterialcharacteristics as predictors. The results show that luthiers are able to estimate wood quality related to visible features, but predictions of mechanical and acoustical properties proved to be very poor.
Some roles of the vocal tract in clarinet breath attacks: Natural sounds analysis and model-based synthesis121(2007); http://dx.doi.org/10.1121/1.2642173View Description Hide Description
A simplified physical model mainly devoted to the reproduction of some transients of clarinet-like instruments is presented. From time-frequency analyses of natural clarinet sounds, it is shown that the vocal tract can play a significant role in some attacks as well as in the permanent regime. The model proposed consists in supplying a pressure source at the entrance of a cylindrical bore attached to the mouthpiece, allowing one to reach various vocal tract configurations. For real-time synthesis purposes, a digital scheme solving the physical problem is proposed. It is shown that this synthesis model is able to reproduce some of the complex features observed during the attacks of the natural sounds analyzed, as well as known effects of the vocal tract in permanent regime.
121(2007); http://dx.doi.org/10.1121/1.2697154View Description Hide Description
Xylophonesounds produced by striking wooden bars with a mallet are strongly influenced by the mechanical properties of the wood species chosen by the xylophone maker. In this paper, we address the relationship between the sound quality based on the timbre attribute of impacted wooden bars and the physical parameters characterizing wood species. For this, a methodology is proposed that associates an analysis-synthesis process and a perceptual classification test. Soundsgenerated by impacting 59 wooden bars of different species but with the same geometry were recorded and classified by a renowned instrument maker. The sounds were further digitally processed and adjusted to the same pitch before being once again classified. The processing is based on a physical model ensuring the main characteristics of the wood are preserved during the sound transformation. Statistical analysis of both classifications showed the influence of the pitch in the xylophone maker judgement and pointed out the importance of two timbre descriptors: the frequency-dependent damping and the spectral bandwidth. These descriptors are linked with physical and anatomical characteristics of wood species, providing new clues in the choice of attractive wood species from a musical point of view.