Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Acoustical effects (3)
- Idiophones (3)
- Musical acoustics (3)
- Musical instruments (3)
- Acoustics (2)
-
- Acoustic Modeling (1)
- Acoustic absorption (1)
- Acoustic modeling (1)
- Acoustic resonance (1)
- Acoustical Measurements (1)
- Acoustical properties (1)
- Acoustical properties Musical instruments (1)
- Architectural acoustics (1)
- Bells (1)
- Biofilms (1)
- Brass Instruments (1)
- Brass instruments (1)
- Brass wind instruments (1)
- COVID-19 (1)
- Chlorhexidine (1)
- Clarinet (1)
- Computational methods (1)
- ESPI (1)
- Elastic constants (1)
- Electromagnetic induction (1)
- Electronic speckle pattern interferometry (1)
- Elephant bells (1)
- Faraday effect (1)
- Ferromagnetism (1)
- Finite element analysis (1)
- Publication Year
Articles 1 - 25 of 25
Full-Text Articles in Physics
Do "Brassy" Sounding Musical Instruments Need Increased Safe Distancing Requirements To Minimize The Spread Of Covid-19?, Thomas R. Moore, Ashley E. Cannaday
Do "Brassy" Sounding Musical Instruments Need Increased Safe Distancing Requirements To Minimize The Spread Of Covid-19?, Thomas R. Moore, Ashley E. Cannaday
Faculty Publications
Brass wind instruments with long sections of cylindrical pipe, such as trumpets and trombones, sound “brassy” when played at a fortissimo level due to the generation of a shock front in the instrument. It has been suggested that these shock fronts may increase the spread of COVID-19 by propelling respiratory particles containing the SARS-CoV-2 virus several meters due to particle entrainment in the low pressure area behind the shocks. To determine the likelihood of this occurring, fluorescent particles, ranging in size from 10–50 lm, were dropped into the shock regions produced by a trombone, a trumpet, and a shock tube. …
A Method For Automatic Detection Of Tongued And Slurred Note Transitions In Clarinet Playing, Whitney L. Coyle, Jack D. Gabriel
A Method For Automatic Detection Of Tongued And Slurred Note Transitions In Clarinet Playing, Whitney L. Coyle, Jack D. Gabriel
Faculty Publications
This study offers a simple method to characterize two transition types in passages of music in order to automatically distinguish slurred transitions from tongued transitions in musical settings. Data were recorded from musicians playing a clarinet with a sensor-equipped mouthpiece measuring blowing pressure in the mouth and pressure in the mouthpiece. This method allows for comparing transitions in different musical contexts, playing regimes, and between players. The method is highly reliable in automatically detecting transition types in recorded clarinet playing in both simple and more complex passages.
The Production Of Phantom Partials Due To Nonlinearities In The Structural Components Of The Piano, Thomas R. Moore, Eric Rokni, Lauren Neldner, Camille Adkison
The Production Of Phantom Partials Due To Nonlinearities In The Structural Components Of The Piano, Thomas R. Moore, Eric Rokni, Lauren Neldner, Camille Adkison
Student-Faculty Collaborative Research Publications
Phantom partials are anomalous overtones in the spectrum of the piano sound that occur at sum and difference frequencies of the natural overtones of the string. Although they are commonly assumed to be produced by forced longitudinal waves in the string, analysis of the sound of a piano produced by mechanically vibrating the soundboard while all the strings are damped indicates that phantom partials can occur in the absence of string motion. The magnitude of the effect leads to the conclusion that nonlinearity in the non-string components may be responsible for some of the power in the phantom partials.
Chlorhexidine-Induced Elastic And Adhesive Changes Of Escherichia Coli Cells Within A Biofilm, Anne E. Murdaugh, Nicole Rodgers
Chlorhexidine-Induced Elastic And Adhesive Changes Of Escherichia Coli Cells Within A Biofilm, Anne E. Murdaugh, Nicole Rodgers
Faculty Publications
Chlorhexidine is a widely used, commercially available cationic antiseptic. Although its mechanism of action on planktonic bacteria has been well explored, far fewer studies have examined its interaction with an established biofilm. The physical effects of chlorhexidine on a biofilm are particularly unknown. Here, the authors report the first observations of chlorhexidine-induced elastic and adhesive changes to single cells within a biofilm. The elastic changes are consistent with the proposed mechanism of action of chlorhexidine. Atomic force microscopy and force spectroscopy techniques were used to determine spring constants and adhesion energy of the individual bacteria within an Escherichia coli biofilm. …
The Singing Cymbal: Is It Really Photon Momentum?, Thomas R. Moore, Samantha Collin, Nikki Etchenique
The Singing Cymbal: Is It Really Photon Momentum?, Thomas R. Moore, Samantha Collin, Nikki Etchenique
Student-Faculty Collaborative Research Publications
A simple demonstration that is occasionally used in the classroom to show that light carries momentum involves making an orchestral cymbal audibly ring using light from a common photoflash. A metal plate or a piece of foil can also be used, however, it appears that many people use a cymbal because the sound is easily heard at a reasonable distance. It is such an impressive example of the effects attributable to photon momentum that it is posted on the CERN website for educational under the name “singing cymbal.” Although it is an impressive demonstration, a series of simple classroom experiments …
Axial Vibrations Of Brass Wind Instrument Bells And Their Acoustical Influence: Theory And Simulations, Wilfried Kausel, Vasileios Chatziioannou, Thomas R. Moore, Britta R. Gorman, Michelle Rokni
Axial Vibrations Of Brass Wind Instrument Bells And Their Acoustical Influence: Theory And Simulations, Wilfried Kausel, Vasileios Chatziioannou, Thomas R. Moore, Britta R. Gorman, Michelle Rokni
Student-Faculty Collaborative Research Publications
Previous work has demonstrated that structural vibrations of brass wind instruments can audibly affect the radiated sound. Furthermore, these broadband effects are not explainable by assuming perfect coincidence of the frequency of elliptical structural modes with air column resonances. In this work a mechanism is proposed that has the potential to explain the broadband influences of structural vibrations on acoustical characteristics such as input impedance, transfer function, and radiated sound. The proposed mechanism involves the coupling of axial bell vibrations to the internal air column. The acoustical effects of such axial bell vibrations have been studied by extending an existing …
Coupling Of Transverse And Longitudinal Waves In Piano Strings, Nikki Etchenique, Samantha Collin, Thomas R. Moore
Coupling Of Transverse And Longitudinal Waves In Piano Strings, Nikki Etchenique, Samantha Collin, Thomas R. Moore
Student-Faculty Collaborative Research Publications
The existence of longitudinal waves in vibrating piano strings has been previously established, as has their importance in producing the characteristic sound of the piano. Modeling of the coupling between the transverse and longitudinal motion of strings indicates that the amplitude of the longitudinal waves are quadratically related to the transverse displacement of the string, however, experimental verification of this relationship is lacking. In the work reported here this relationship is tested by driving the transverse motion of a piano string at only two frequencies, which simplifies the task of unambiguously identifying the constituent signals. The results indicate that the …
Axial Vibrations Of Brass Wind Instrument Bells And Their Acoustical Influence: Experiments, Thomas R. Moore, Britta R. Gorman, Michelle Rokni, Wilfried Kausel, Vasileios Chatziioannou
Axial Vibrations Of Brass Wind Instrument Bells And Their Acoustical Influence: Experiments, Thomas R. Moore, Britta R. Gorman, Michelle Rokni, Wilfried Kausel, Vasileios Chatziioannou
Faculty Publications
It has recently been proposed that the effects of structural vibrations on the radiated sound ofbrass wind instruments may be attributable to axial modes of vibration with mode shapes that contain no radial nodes [Kausel, Chatziioannou, Moore, Gorman, and Rokni, J. Acoust. Soc. Am.137, 3149–3162 (2015)]. Results of experiments are reported that support this theory. Mechanical measurements of a trumpet bell demonstrate that these axial modes do exist inbrass wind instruments. The quality factor of the mechanical resonances can be on the order of 10 or less, making them broad enough to encompass the frequency range of previously reported effects …
Normal Modes Of A Small Gamelan Gong, Robert Perrin, Daniel Elford, Luke Chambers, Gerry M. Swallowe, Thomas R. Moore, Sinin Hamdan, Benjamin J. Halkon
Normal Modes Of A Small Gamelan Gong, Robert Perrin, Daniel Elford, Luke Chambers, Gerry M. Swallowe, Thomas R. Moore, Sinin Hamdan, Benjamin J. Halkon
Faculty Publications
Studies have been made of the normal modes of a 20.7 cm diameter steel gamelan gong. A finite-element model has been constructed and its predictions for normal modes compared with experimental results obtained using electronic speckle pattern interferometry. Agreement was reasonable in view of the lack of precision in the manufacture of the instrument. The results agree with expectations for an axially symmetric system subject to small symmetry breaking. The extent to which the results obey Chladni's law is discussed. Comparison with vibrational and acoustical spectra enabled the identification of the small number of modes responsible for the sound output …
A Simple And Inexpensive Optical Technique To Help Students Visualize Mode Shapes, Thomas R. Moore, Ashley E. Cannaday, Sarah A. Zietlow
A Simple And Inexpensive Optical Technique To Help Students Visualize Mode Shapes, Thomas R. Moore, Ashley E. Cannaday, Sarah A. Zietlow
Student-Faculty Collaborative Research Publications
An imaging technique is introduced that is suitable for visualizing the mode shapes of vibrating structures in an educational setting. The method produces images similar to those obtained using electronic speckle pattern interferometry (ESPI) but it can be implemented for less than 1=10 the cost of a commercial ESPI system, and the apparatus is simple enough that it can be constructed by undergraduate students. This technique allows for real-time visualization of the normal modes and detection shapes of harmonically vibrating structures, including those with shapes that make generating Chladni patterns with sand or powder impossible. The theory of operation and …
Normal Modes Of The Indian Elephant Bell, Robert Perrin, Luke Chalmers, Daniel Elford, Gerry M. Swallowe, Thomas R. Moore
Normal Modes Of The Indian Elephant Bell, Robert Perrin, Luke Chalmers, Daniel Elford, Gerry M. Swallowe, Thomas R. Moore
Faculty Publications
The geometrical structure of the Indian elephant bell is presented and the requirements on its normal modes from group representation theory are described. These are in good agreement with the results of a finiteelement model (FEM) for a specific 16-tine case. The spectrum consists of a sequence of families of modes lying on saturation curves and so is completely different from those of conventional bells. Physical explanations for the occurrence of these families are presented in terms of the tines behaving as a closed loop of coupled cantilevers with constraints from the dome. Each family is found to consist of …
The Limitations On Applying Classical Thin Plate Theory To Thin Annular Plates Clamped On The Inner Boundary, Daniel W. Zietlow, Donald C. Griffin, Thomas R. Moore
The Limitations On Applying Classical Thin Plate Theory To Thin Annular Plates Clamped On The Inner Boundary, Daniel W. Zietlow, Donald C. Griffin, Thomas R. Moore
Student-Faculty Collaborative Research Publications
The experimentally measured resonance frequencies of a thin annular plate with a small ratio of inner to outer radii and clamped on the inner boundary are compared to the predictions of classical thin-plate (CTP) theory and a finite-element (FE) model. The results indicate that, contrary to the conclusions presented in a number of publications, CTP theory does not accurately predict the frequencies of a relatively small number of resonant modes at lower frequencies. It is shown that these inaccuracies are attributable to shear deformations, which are thought to be negligible in thin plates and are neglected in CTP theory. Of …
Measurement Of The Elastic Tensor Of Smsco3 And Ndsco3 Using Resonant Ultrasound Spectroscopy With Ab Initio Calculations, Kenneth A. Pestka, Eric S. Scott, Y Lepage
Measurement Of The Elastic Tensor Of Smsco3 And Ndsco3 Using Resonant Ultrasound Spectroscopy With Ab Initio Calculations, Kenneth A. Pestka, Eric S. Scott, Y Lepage
Student-Faculty Collaborative Research Publications
The complete elastic tensors of SmScO3 and NdScO3 were measured using resonant ultrasound spectroscopy (RUS) in combination with ab-initio calculations. Measurement of the elastic tensor of these recently synthesized single crystal RE scandates is essential for understanding dynamic lattice applications including phonon confinement, strain induced thin film growth and superlattice construction. On average, the experimental elastic constants differed by less than 5% of the theoretical values, further validating the accuracy of modern ab-initio calculations as a means of estimating the initial elastic constants used in RUS measurements.
Influence Of Wall Vibrations On The Sound Of Brass Wind Instruments, Wilfried Kausel, Daniel W. Zietlow, Thomas R. Moore
Influence Of Wall Vibrations On The Sound Of Brass Wind Instruments, Wilfried Kausel, Daniel W. Zietlow, Thomas R. Moore
Student-Faculty Collaborative Research Publications
The results of an experimental and theoretical investigation of the influence of wall vibrations on the sound of brass wind instruments are presented. Measurements of the transmission function and input impedance of a trumpet, with the bell both heavily damped and freely vibrating, are shown to be consistent with a theory that assumes that the internal pressure causes an oscillation of the diameter of the pipe enclosing the air column. These effects are shown to be most significant in sections where there are flaring walls, which explains why damping these vibrations in cylindrical pipes normally produces no measurable effects.
Imaging Of Vibrating Objects Using Speckle Subtraction, Thomas R. Moore, Ashley E. Cannaday, Sarah A. Zietlow
Imaging Of Vibrating Objects Using Speckle Subtraction, Thomas R. Moore, Ashley E. Cannaday, Sarah A. Zietlow
Student-Faculty Collaborative Research Publications
A simple method for imaging vibrational motion is proposed. The process consists of capturing two speckled images of a region illuminated by coherent radiation. One of the images is captured before the onset of motion and the other during motion. If the mean speckle intensity is below the threshold for detection or above the saturation intensity of the detector, subtracting the two images produces a high contrast image of the moving region. A theory is shown to agree well with experimental data.
Modeling The Magnetic Pickup Of An Electric Guitar, Nicholas G. Horton, Thomas R. Moore
Modeling The Magnetic Pickup Of An Electric Guitar, Nicholas G. Horton, Thomas R. Moore
Student-Faculty Collaborative Research Publications
The magnetic pickup of an electric guitar uses electromagnetic induction to convert the motion of a ferromagnetic guitar string into an electrical signal. Although the magnetic pickup is often cited as an everyday application of Faraday's law, few sources mention the distortion that the pickup generates when converting string motion into an electric signal, and even fewer attempt to analyze and explain this distortion. By modeling the magnet and ferromagnetic wire as surfaces with magnetic charge, an intuitive model that accurately predicts the output of a magnetic guitar pickup can be constructed. More
importantly, this model can be understood and …
Transient Motion Of A Circular Plate After An Impact, Thomas R. Moore, Daniel W. Zietlow, Christopher W. Gorman, Donald C. Griffin, Connor P. Ballance, David J. Parker
Transient Motion Of A Circular Plate After An Impact, Thomas R. Moore, Daniel W. Zietlow, Christopher W. Gorman, Donald C. Griffin, Connor P. Ballance, David J. Parker
Student-Faculty Collaborative Research Publications
The transient response of a flat circular plate to a sudden impact has been studied experimentally and theoretically. High-speed electronic speckle pattern interferometry reveals the presence of pulses that travel around the edge of the plate ahead of the bending motion initiated by the strike. It is found that the transient motion of the plate is well described by Kirchhoff thin-plate theory over a time approximately equal to the time required for the initial impulse to circumvent the plate; however, a more sophisticated model is required to describe the motion after this time has elapsed.
Time-Averaged Electronic Speckle Pattern Interferometry In The Presence Of Ambient Motion. Part I: Theory And Experiments, Thomas R. Moore, Jacob J. Skubal
Time-Averaged Electronic Speckle Pattern Interferometry In The Presence Of Ambient Motion. Part I: Theory And Experiments, Thomas R. Moore, Jacob J. Skubal
Student-Faculty Collaborative Research Publications
An electronic speckle pattern interferometer is introduced that can produce time-averaged interferograms of harmonically vibrating objects in instances where it is impractical to isolate the object from ambient vibrations. By subtracting two images of the oscillating object, rather than the more common technique of subtracting an image of the oscillating object from one of the static objects, interferograms are produced with excellent visibility even when the object is moving relative to the interferometer. This interferometer is analyzed theoretically and the theory is validated experimentally.
Experimental Investigation Of An American Five-String Banjo, Laurie A. Stephey, Thomas R. Moore
Experimental Investigation Of An American Five-String Banjo, Laurie A. Stephey, Thomas R. Moore
Student-Faculty Collaborative Research Publications
An experimental investigation of an American five-string banjo is reported. The acoustic spectra of the strings are analyzed and it is found that in many ways banjo strings behave in a manner similar to those on a piano. The terminating impedance presented to the strings at the bridge is reported and it is found to be generally much lower than the characteristic impedance of the strings. It is also shown that, for a properly tuned banjo, the mode shapes of the membrane are symmetric about the center even though there is a large asymmetric force due to the off-center placement …
The Normal Modes Of Cymbals, Robert Perrin, Gerry M. Swallowe, Sarah A. Zietlow, Thomas R. Moore
The Normal Modes Of Cymbals, Robert Perrin, Gerry M. Swallowe, Sarah A. Zietlow, Thomas R. Moore
Student-Faculty Collaborative Research Publications
No abstract provided.
Interferometric Studies Of A Piano Soundboard, Thomas R. Moore, Sarah A. Zietlow
Interferometric Studies Of A Piano Soundboard, Thomas R. Moore, Sarah A. Zietlow
Student-Faculty Collaborative Research Publications
Electronic speckle pattern interferometry has been used to study the deflection shapes of a piano soundboard. A design for an interferometer that can image such an unstable object is introduced, and interferograms of a piano soundboard obtained using this interferometer are presented. Deflection shapes are analyzed and compared to a finite element model, and it is shown that the force the strings exert on the soundboard is important in determining the mode shapes and resonant frequencies. Measurements of resonance frequencies and driving point impedance made using the interferometer are also presented.
The Effects Of Bell Vibrations On The Sound Of The Modern Trumpet, Thomas R. Moore, Erin T. Shirley, Isaac E. W. Codrey, Amy E. Daniels
The Effects Of Bell Vibrations On The Sound Of The Modern Trumpet, Thomas R. Moore, Erin T. Shirley, Isaac E. W. Codrey, Amy E. Daniels
Student-Faculty Collaborative Research Publications
The acoustic spectrum of a modern trumpet with the bell section heavily damped has been compared to the spectrum of the same instrument with the bell section left free to vibrate. Measurements of the amplitude of vibration indicate that the damping significantly reduces the movement of the metal, and a corresponding change in the acoustic spectrum between the two cases is found. It is shown that the relative power in the fundamental may change by more than 3 dB when the vibrations in the bell section are damped. Two possible causes for the effects are considered: a change in input …
The Dynamics And Tuning Of Orchestral Crotales, Bradley M. Deutsch, Cherie L. Ramirez, Thomas R. Moore
The Dynamics And Tuning Of Orchestral Crotales, Bradley M. Deutsch, Cherie L. Ramirez, Thomas R. Moore
Student-Faculty Collaborative Research Publications
Crotales are center-weighted, tuned cymbals that are found in the percussion section of most orchestras. They are arranged like a keyboard in octave sets and are commercially available in two octaves, from C6 to C8. Little information about the physics of crotales has been reported in the literature, despite their having the interesting property of producing a particularly pleasing sound. In this study, the acoustic and vibrational properties of crotales from C6 to C8 are theoretically and experimentally investigated. Interferograms of typical vibrational modes are presented, and the frequencies of the acoustically important modes of crotales are identified and reported. …
A Simple Design For An Electronic Speckle Pattern Interferometer, Thomas R. Moore
A Simple Design For An Electronic Speckle Pattern Interferometer, Thomas R. Moore
Faculty Publications
An electronic speckle pattern interferometer suitable for use in an undergraduate laboratory is described. This interferometer can be built for a small fraction of the cost of a commercial version and is simple and inexpensive to build and understand. The interferometer is useful for visualizing the normal modes of vibrating objects as well as changes in index of refraction.
Non-Degenerate Normal-Mode Doublets In Vibrating Flat Circular Plates, Bradley M. Deutsch, Alexandra R. Robinson, Richard J. Felce, Thomas R. Moore
Non-Degenerate Normal-Mode Doublets In Vibrating Flat Circular Plates, Bradley M. Deutsch, Alexandra R. Robinson, Richard J. Felce, Thomas R. Moore
Student-Faculty Collaborative Research Publications
The vibrations of flat circular plates have been studied for hundreds of years, and they are well understood by the scientific community. Unfortunately, when vibrating circular plates are discussed in textbooks, the relationship between pairs of spatially orthogonal vibrational patterns that occur at each of the normal-mode frequencies is often ignored. Usually these orthogonal solutions are presented to the student as being degenerate in frequency; however, in practice the degeneracy of the doublet is often broken and the two spatially orthogonal solutions are separated in frequency. We show theoretically and experimentally that the degeneracy can be broken by a small …