Play that funky music: Making 3D acoustic measurements of instruments under performance conditions.

This research involves the design and implementation of a high spatial resolution acoustic radiation measurement system for the purpose of collecting data about the acoustic radiation in 3 dimensions from musical instruments while they are being played by musicians. It is also possible for the system to be used to capture 3 dimensional data about other sound sources. Each musician may, when they perform upon their instrument, attempt to play consistently with the same dynamics and tone, the same timing and feeling, but will ultimately fail. This is not a failing in the musician themselves, but rather a function of the fact that musicians are, like all people, biological beings, and therefore cannot perform exactly the same movement with the consistency required for scientific data gathering when the purpose of the movement is to actuate another object (the instrument in this case). The problem has been attempted to be solved by taking the musician out of the measurement process, and by mechanically actuating the instrument in order to make repeatable and consistent measurements, but this rather defeats the purpose, as the instrument will not play (in performance) without the musician present. The very presence of the musician will change the acoustic behaviour of the musical instrument as the musician will absorb some of the acoustic energy radiated from the instrument, especially at high frequencies, and to a lesser extent, the mid-range and lower frequencies within the audible spectrum. (This is related to the physical wavelength of the sound pressure wave – where it is smaller than the dimensions of the human body of the musician it will tend to be absorbed, but when longer it will tend to diffract around the body and will not be absorbed much, if at all). So, it has been proposed to make the acoustic radiation measurement system compatible with an instrument actually being played. This will involve a grid of sensors which surround the musician, taking measurements of data at spatially averaged points, but with higher spatial resolution than in any of the previously surveyed literature. This will allow the interpolation of that data in order to predict the frequency-amplitude response and the phase of those frequency components in any given direction around the instrument (or other sound source) which has been measured. In order to make high resolution measurements of the acoustic behaviour of musical instruments under performance conditions, a measurement system has been designed which consists of a number of interconnected parts. These include the sensors arranged in array on a 3 dimensional grid, signal conditioning circuits to bias the sensors, a set of analogue to digital convertors to send the signals to the data capture devices, and an array of hard disk data recorders to capture the data being generated by the sensors. When the data is captured, it can be then organised, processed, analysed and displayed in various ways

Sensor Grid Design For High Resolution 3D Acoustic Measurements Of Musical Instruments.

Much of the research undertaken in the field of musical acoustic analysis involves (electro)mechanical actuation of the instruments under measurement conditions without the musician present. This has the benefit of repeatability, so that apparatus can be designed in order to make asynchronous measurements at different points in 3D space. It also means that the instrument is analysed in its pure form without any acoustic aberrations presented by a human performer. However it has been found that when a musician performs on the instrument, this repeatability is absent (despite the musician’s self-belief in their own consistency) and an alternative approach must be taken to make 3-dimensional acoustic measurements with the musician present. Musicians could of course be present during actuated musical instrument analysis but this is not (yet) a common approach. The research project described in this paper is ongoing and recent developments of sensor grid geometry are presented here along with some promising initial results. The sensor array geometry has been investigated with respect to: optimal spacing, minimising errors in data interpolation at high frequency, and practicality for construction and actual use. Some preliminary data from a section of the array grid has been obtained and is presented here in order to demonstrate the robustness of the data at high frequencies. There is some discussion of the likely errors in interpolation of the data and some further ideas are explored regarding the manipulation of the recorded data

Flying solo: Elevating student sound engineers into responsible work experience roles at live music events

The role of live sound mixer is somewhat akin to piloting an aeroplane full of passengers: you are in control of the outcome for a number of people for a certain time, and must take in a lot of sensory information, process and act upon it using highly technical controls and equipment. Work experience students at live events often work up to this role and have to undertake more menial tasks such as running cables, moving loudspeakers and other equipment, loading vans and trucks; even on a long-term placement. However, by taking the lead from pilot training where the learner takes the controls under supervision of a more experienced professional pilot, student sound engineers can assume control of a live mix with an audience present while benefitting from the guidance of a professional. This article discusses such an approach in the context of its place within or alongside the curriculum

Sensor grid design for high resolution 3D acoustic measurements of musical instruments

[Paper presented at the Institute of Acoustics 2019 Conference, held in Milton Keynes, 13-14 May 2019.

PKAN neurodegeneration and residual PANK2 activities in patient erythrocytes

Objective: Pantothenate kinase 2-associated neurodegeneration (PKAN) is a rare neurodegenerative disease caused by mutations in the pantothenate kinase 2 (PANK2) gene. PKAN is associated with iron deposition in the basal ganglia and, occasionally, with the occurrence of misshaped erythrocytes (acanthocytes). The aim of this study was to assess residual activity of PANK2 in erythrocytes of PKAN patients and to correlate these data with the type of PANK2 mutations and the progression of neurodegeneration. Methods: Residual PANK2 activities in erythrocytes of 14 PKAN patients and 14 related carriers were assessed by a radiometric assay. Clinical data on neurodegeneration included the Barry-Albright Dystonia Scale (BAD-Scale) besides further general patient features. A molecular visualization and analysis program was used to rationalize the influence of the PKAN causing mutations on a molecular level. Results: Erythrocytes of PKAN patients had markedly reduced or no PANK2 activity. However, patients with at least one allele of the c.1583C > T (T528M) or the c.833G > T (R278L) variant exhibited 12-56% of residual PANK2 activity. In line, molecular modeling indicated only minor effects on enzyme structure for these point mutations. On average, these patients with c.1583C > T or c.833G > T variant had lower BAD scores corresponding to lower symptom severity than patients with other PANK2 point mutations. Interpretation: Residual erythrocyte PANK2 activity could be a predictor for the progression of neurodegeneration in PKAN patients. Erythrocytes are an interesting patient-derived cell system with still underestimated diagnostic potential

Bringing KASH under the SUN: the many faces of nucleo-cytoskeletal connections

The nucleus is the most prominent cellular organelle, and its sharp boundaries suggest the compartmentalization of the nucleoplasm from the cytoplasm. However, the recent identification of evolutionarily conserved linkers of the nucleoskeleton to the cytoskeleton (LINC) complexes, a family of macromolecular assemblies that span the double membrane of the nuclear envelope, reveals tight physical connections between the two compartments. Here, we review the structure and evolutionary conservation of SUN and KASH domain–containing proteins, whose interaction within the perinuclear space forms the “nuts and bolts” of LINC complexes. Moreover, we discuss the function of these complexes in nuclear, centrosomal, and chromosome dynamics, and their connection to human disease

High Resolution Acoustic Measurements of Musical Instruments

This thesis presents the work undertaken while carrying out research into acoustic measurement techniques for 3-dimensional acoustic radiation data for musical instruments, specifically when the instruments are being played by musicians. The original contribution to knowledge that is presented includes the development of an algorithm which can be used for post-processing of recorded data to obtain signals from ‘virtual’ microphones. The project is discussed along with a rationale for the particular test and measurement procedure used in this research and is followed by a literature review outlining both historical and current research and writing relevant to the project. A design for high spatial resolution 3-D acoustic measurement apparatus is proposed, and the design details and construction methods are discussed. The measurement process is described, including the issues surrounding testing and the use of human musicians in the measurement of musical instrument acoustic radiation patterns. A novel algorithm is presented which applies transfer functions derived from interpolated measured data points in order to process recorded audio signals with applications in audio post-production. A prototype implementation of the algorithm is described along with its testing. The conclusion summarises the thesis; contains an evaluation of the work undertaken and the results; and explores potential future work from this project