No description available.

No description available.

No description available.

Theis(MMus) -- Stellenbosch University, 1983. / No Abstract Available

The purposes of this study were (1) to categorize examples of vowel sounds by means of subjective evaluation, (2) to ascertain by spectrographic analysis the distinguishing characteristics of the acoustical properties of the examples in the categories, (3) to determine the similarities and dissimilarities which exist within and between the categories, and (4) to analyze the implications of the findings for the teaching of choral singing.

A well-made flute is always a compromise and the job of flute makers is to achieve a musically and aesthetically satisfying compromise; a task that involves much trial and-error. The practical aim of this thesis is to develop a mathematical model of the flute and a computer program that assists in the flute design process. Many musical qualities of a woodwind instrument may be calculated from the acoustic impedance spectrum of the instrument. A technique for fast and accurate measurement of this quantity is developed. The technique is based on the multiple-microphone technique, and uses resonance-free impedance loads to calibrate the system and spectral shaping to improve the precision at impedance extrema. The impedance spectra of the flute and clarinet are measured over a wide range of fingerings, yielding a comprehensive and accurate database. The impedance properties of single finger holes are measured using a related technique, and fitformulae are derived for the length corrections of closed finger holes for a typical range of hole sizes and lengths. The bore surface of wooden instruments can change over time with playing and this can affect the acoustic impedance, and therefore the playing quality. Such changes in acoustic impedance are explored using wooden test pipes. To account for the effect of a typical player on flute tuning, an empirical correction is determined from the measured tuning of both modern and classical flutes as played by several professional and semi-professional players. By combining the measured impedance database with the player effects and various results in the literature a mathematical model of the input impedance of flutes is developed and implemented in command-line programs written in the software language C. A user-friendly graphical interface is created using the flute impedance model for the purposes of flute acoustical design and analysis. The program calculates the tuning and other acoustical properties for any given geometry. The program is applied to a modern flute and a classical flute. The capabilities and limitations of the software are thereby illustrated and possible contributions of the program to contemporary flute design are explored.

"...music is an art that exists in point of time." Aaron Copland, What to Listen for in Music / Few definitions are adequate to describe music, but a "point of time" is a concept with which people are familiar. When musicians give concerts they try to create these points in a context, which allows the audience to observe each moment by itself. Concert practice has developed to define the edges of musical points, guided by cues such as clapping, pauses, and concert program notes. / This masters thesis investigates how to analyze concert recordings of Western music and their program notes to produce segments which best fit the boundaries of musical points. Modern segmentation techniques are reviewed and a new method specific to concert recordings is examined.

The objective of this research is to improve the analysis of musical sounds in comparison to traditional additive analysis, i.e. Fourier Analysis. Namely, the focus of this study is to improve the tracking of time-evolving partials. Traditional analysis methods assume constant amplitudes and frequencies over each successive frame in which a signal is analyzed. Tracking the time-evolution of these partials, however, can require the implementation of complex probabilistic techniques. This thesis presents an alternative method in which the Ambiguity Function, a distribution in both time and frequency, is used to create a clearer, more accurate representation that requires fewer complex methods to track partials. Through the use of a more accurate spectral representation and the inclusion of a chirp rate parameter, partials may be more readily followed based upon spectral parameters alone. This new method that is presented will build upon the traditional methods by first employing Fourier analysis to identify partials, and then utilizing the Analytic Signal and Ambiguity Function to improve individual spectral parameter estimations and partial tracking. The overall intent of this work is that through this method, one may create an improved spectral model that is more useful to musical analysis.

A well-made flute is always a compromise and the job of flute makers is to achieve a musically and aesthetically satisfying compromise; a task that involves much trial and-error. The practical aim of this thesis is to develop a mathematical model of the flute and a computer program that assists in the flute design process. Many musical qualities of a woodwind instrument may be calculated from the acoustic impedance spectrum of the instrument. A technique for fast and accurate measurement of this quantity is developed. The technique is based on the multiple-microphone technique, and uses resonance-free impedance loads to calibrate the system and spectral shaping to improve the precision at impedance extrema. The impedance spectra of the flute and clarinet are measured over a wide range of fingerings, yielding a comprehensive and accurate database. The impedance properties of single finger holes are measured using a related technique, and fitformulae are derived for the length corrections of closed finger holes for a typical range of hole sizes and lengths. The bore surface of wooden instruments can change over time with playing and this can affect the acoustic impedance, and therefore the playing quality. Such changes in acoustic impedance are explored using wooden test pipes. To account for the effect of a typical player on flute tuning, an empirical correction is determined from the measured tuning of both modern and classical flutes as played by several professional and semi-professional players. By combining the measured impedance database with the player effects and various results in the literature a mathematical model of the input impedance of flutes is developed and implemented in command-line programs written in the software language C. A user-friendly graphical interface is created using the flute impedance model for the purposes of flute acoustical design and analysis. The program calculates the tuning and other acoustical properties for any given geometry. The program is applied to a modern flute and a classical flute. The capabilities and limitations of the software are thereby illustrated and possible contributions of the program to contemporary flute design are explored.

A brief overview of the workings of the human auditory system is followed by a review of literature concerning both the theories and experimental investigations of human pitch perception. The application of these theories to the inharmonic complex tones produced by bells is discussed, and further experiments using bell sounds are reviewed. A methodology for psychoacoustic experiments with specific reference to those investigating pitch perception of inharmonic complex tones is presented. This methodology is then implemented in an experimental investigation of pitch perception of ringing and chiming bell sounds. A pitch matching experiment using ringing and chiming sounds from four bells aimed to determine perceived pitch differences between ringing and chiming bells. This experiment was inconclusive because insufficient data was collected. Known experimental results, such as the inability of non-musicians to match the pitches of sounds with different timbres were confirmed. Spectral analyses of the stimuli were performed. The presentation of stimuli at a low level of sensation is questioned, as this might have prevented pseudo high frequency noise resulting from stronger upper partials in the ringing sound from being audible, and hence the pitch differences between ringing and chiming bells would not be observed.