Efficiency of Detection of Commercial Items with Acoustic Instruments

2006 ◽  
pp. 83-104
Author(s):  
I.L. Kalikhman ◽  
K.I. Yudanov
Keyword(s):  
Acoustic Instruments

scholarly journals Sparse pursuit and dictionary learning for blind source separation in polyphonic music recordings

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Sören Schulze ◽  
Emily J. King
Keyword(s):  
Single Channel ◽  
Spectral Characteristics ◽  
Musical Instruments ◽  
Model Parameters ◽  
Blind Separation ◽  
Audio Signals ◽  
Frequency Spectra ◽  
Acoustic Instruments ◽  
Invariant Properties ◽  
Music Recordings

AbstractWe propose an algorithm for the blind separation of single-channel audio signals. It is based on a parametric model that describes the spectral properties of the sounds of musical instruments independently of pitch. We develop a novel sparse pursuit algorithm that can match the discrete frequency spectra from the recorded signal with the continuous spectra delivered by the model. We first use this algorithm to convert an STFT spectrogram from the recording into a novel form of log-frequency spectrogram whose resolution exceeds that of the mel spectrogram. We then make use of the pitch-invariant properties of that representation in order to identify the sounds of the instruments via the same sparse pursuit method. As the model parameters which characterize the musical instruments are not known beforehand, we train a dictionary that contains them, using a modified version of Adam. Applying the algorithm on various audio samples, we find that it is capable of producing high-quality separation results when the model assumptions are satisfied and the instruments are clearly distinguishable, but combinations of instruments with similar spectral characteristics pose a conceptual difficulty. While a key feature of the model is that it explicitly models inharmonicity, its presence can also still impede performance of the sparse pursuit algorithm. In general, due to its pitch-invariance, our method is especially suitable for dealing with spectra from acoustic instruments, requiring only a minimal number of hyperparameters to be preset. Additionally, we demonstrate that the dictionary that is constructed for one recording can be applied to a different recording with similar instruments without additional training.

Piano+: An Approach towards a Performance System Used within Free Improvisation

2010 ◽  
Vol 20 ◽  
pp. 41-46
Author(s):  
Sebastian Lexer
Keyword(s):  
Decision Making ◽  
Parameter Space ◽  
Social Space ◽  
Computer Performance ◽  
Free Improvisation ◽  
Technical Realization ◽  
Acoustic Instruments ◽  
Performance System ◽  
And Behavior ◽  
Computer Operation

This article explores the author's strategy for developing a computer performance system designed for free improvisation with acoustic instruments following a non-idiomatic approach. Philosophical considerations on potentiality and personal and social space and research into the psychology of motivation and behavior have inspired and enabled a different approach to integrating technology with improvisation. The technical realization of a parameter space, in particular utilizing contingent behavior emerging from the convergent mapping of a mixture of controller types, has proven effective for the spontaneous creative decision making required to extend the sonic potential of an acoustic piano while minimizing direct computer operation, as applied regularly in practice by the author.

Timbral Thievery

2018 ◽  
Author(s):  
Jonathan De Souza
Keyword(s):  
Nineteenth Century ◽  
Twentieth Century ◽  
Tuning Fork ◽  
Sound Sources ◽  
Hermann Von Helmholtz ◽  
Milton Babbitt ◽  
Acoustic Instruments

Timbre often indexes an instrument’s materiality, and timbral variation often correlates with a player’s actions. Yet synthesizers complicate phenomenological links between sound and source. This chapter juxtaposes three instruments: an electromagnetic tuning-fork apparatus, developed by the nineteenth-century scientist Hermann von Helmholtz; the RCA Mark II, used by Milton Babbitt and other mid-twentieth-century composers; and the Yamaha GX-1, a large polyphonic synthesizer from the 1970s, played by Stevie Wonder and Keith Emerson. These synthesizers create new timbres and also imitate acoustic instruments, in a process that Robert Moog calls “timbral thievery.” Such imitations can provoke exaggerated or anxious discussions of synthetic and natural timbre. At the same time, performers may showcase the gap between timbre and instrument, exploiting a sense of uncanny or ambiguous sound sources for varied expressive ends. Ultimately, then, synthesizers help musicians both produce and conceptualize timbre.

Acoustic instruments

1992 ◽  
pp. 45-88
Author(s):  
David N. MacLennan ◽  
E. John Simmonds
Keyword(s):  
Acoustic Instruments

An empirical investigation of pause notation

Pragmatics ◽  
2002 ◽  
Vol 12 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Anna-Marie R. Spinos ◽  
Daniel C. O’Connell ◽  
Sabine Kowal
Keyword(s):  
English Language ◽  
Empirical Investigation ◽  
Relative Length ◽  
Pause Duration ◽  
False Positives ◽  
Perceptual Judgment ◽  
Articulation Rate ◽  
Acoustic Instruments ◽  
Instrumental Measurement ◽  
Current Article

The current article examines the limitations of perceptual judgment for the transcription of pause occurrence and duration. This investigation extends Kowal and O’Connell’s (2000) previous research, which examined pause occurrence and duration notated by perceptual judgment with measurements from acoustic instruments for three corpora. Kowal and O’Connell found that, across corpora, there were a notable number of errors in perceptual detection of pauses, including both failure to notate pauses measurable with instrumentation (misses) and notation of pauses that were not measurable (false positives). In this study we focus on pause transcription in a uniquely English-language database, examining four excerpts from the London-Lund Corpus (LLC). Pauses which had been notated perceptually in LLC were compared with pause measurements from a Siemens Oscillomink L. As in the previous research, it was found that a notable number of pauses detectable with the acoustic instruments were not notated in LLC, which relied on only perceptual judgment. Errors in pause detection, both false positives and misses, accounted for 86 cases over 257 perceptually notated pauses, an error rate of one in three. We also examined two assumptions of LLC: (1) The assumption that perceptually notated pauses would adhere to interval scaling was not substantiated by instrumental measurement. (2) The assumption (Crystal and Quirk 1964: 49) that “impressionistic relative length varies with the tempo norm of a given speaker” was also not substantiated insofar as all correlations of tempo (operationalized as articulation rate) with ambient pause duration were nonsignificant.

Estimation of clock drift in underwater acoustic instruments using propagation channel analysis

2017 ◽  
Vol 141 (5) ◽  
pp. 3990-3990
Author(s):  
Ilya A. Udovydchenkov ◽  
Ballard J. Blair ◽  
Ralph A. Stephen ◽  
Peter F. Worcester ◽  
Matthew Dzieciuch
Keyword(s):  
Propagation Channel ◽  
Underwater Acoustic ◽  
Clock Drift ◽  
Acoustic Instruments ◽  
Channel Analysis
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