9,941 research outputs found
Computer Models for Musical Instrument Identification
PhDA particular aspect in the perception of sound is concerned with what is commonly
termed as texture or timbre. From a perceptual perspective, timbre is what allows us
to distinguish sounds that have similar pitch and loudness. Indeed most people are
able to discern a piano tone from a violin tone or able to distinguish different voices
or singers.
This thesis deals with timbre modelling. Specifically, the formant theory of timbre
is the main theme throughout. This theory states that acoustic musical instrument
sounds can be characterised by their formant structures. Following this principle, the
central point of our approach is to propose a computer implementation for building
musical instrument identification and classification systems.
Although the main thrust of this thesis is to propose a coherent and unified
approach to the musical instrument identification problem, it is oriented towards the
development of algorithms that can be used in Music Information Retrieval (MIR)
frameworks. Drawing on research in speech processing, a complete supervised system
taking into account both physical and perceptual aspects of timbre is described.
The approach is composed of three distinct processing layers. Parametric models
that allow us to represent signals through mid-level physical and perceptual representations
are considered. Next, the use of the Line Spectrum Frequencies as spectral
envelope and formant descriptors is emphasised. Finally, the use of generative and
discriminative techniques for building instrument and database models is investigated.
Our system is evaluated under realistic recording conditions using databases of isolated
notes and melodic phrases
Waveguide physical modeling of vocal tract acoustics: flexible formant bandwidth control from increased model dimensionality
Digital waveguide physical modeling is often used as an efficient representation of acoustical resonators such as the human vocal tract. Building on the basic one-dimensional (1-D) Kelly-Lochbaum tract model, various speech synthesis techniques demonstrate improvements to the wave scattering mechanisms in order to better approximate wave propagation in the complex vocal system. Some of these techniques are discussed in this paper, with particular reference to an alternative approach in the form of a two-dimensional waveguide mesh model. Emphasis is placed on its ability to produce vowel spectra similar to that which would be present in natural speech, and how it improves upon the 1-D model. Tract area function is accommodated as model width, rather than translated into acoustic impedance, and as such offers extra control as an additional bounding limit to the model. Results show that the two-dimensional (2-D) model introduces approximately linear control over formant bandwidths leading to attainable realistic values across a range of vowels. Similarly, the 2-D model allows for application of theoretical reflection values within the tract, which when applied to the 1-D model result in small formant bandwidths, and, hence, unnatural sounding synthesized vowels
Extended pipeline for content-based feature engineering in music genre recognition
We present a feature engineering pipeline for the construction of musical
signal characteristics, to be used for the design of a supervised model for
musical genre identification. The key idea is to extend the traditional
two-step process of extraction and classification with additive stand-alone
phases which are no longer organized in a waterfall scheme. The whole system is
realized by traversing backtrack arrows and cycles between various stages. In
order to give a compact and effective representation of the features, the
standard early temporal integration is combined with other selection and
extraction phases: on the one hand, the selection of the most meaningful
characteristics based on information gain, and on the other hand, the inclusion
of the nonlinear correlation between this subset of features, determined by an
autoencoder. The results of the experiments conducted on GTZAN dataset reveal a
noticeable contribution of this methodology towards the model's performance in
classification task.Comment: ICASSP 201
Classification of Musical Instruments sounds by Using MFCC and Timbral Audio Descriptors
Identification of the musical instrument from a music piece is becoming area of interest for researchers in recent years. The system for identification of musical instrument from monophonic audio recording is basically performs three tasks: i) Pre-processing of inputted music signal; ii) Feature extraction from the music signal; iii) Classification. There are many methods to extract the audio features from an audio recording like Mel-frequency Cepstral Coefficients (MFCC), Linear Predictive Codes (LPC), Linear Predictive Cepstral Coefficients (LPCC), Perceptual Linear Predictive Coefficients (PLP), etc. The paper presents an idea to identify musical instruments from monophonic audio recordings by extracting MFCC features and timbre related audio descriptors. Further, three classifiers K-Nearest Neighbors (K-NN), Support Vector Machine (SVM) and Binary Tree Classifier (BT) are used to identify the musical instrument name by using feature vector generated in feature extraction process. The analysis is made by studying results obtained by all possible combinations of feature extraction methods and classifiers. Percentage accuracies for each combination are calculated to find out which combinations can give better musical instrument identification results. The system gives higher percentage accuracies of 90.00%, 77.00% and 75.33% for five, ten and fifteen musical instruments respectively if MFCC is used with K-NN classifier and for Timbral ADs higher percentage accuracies of 88.00%, 84.00% and 73.33% are obtained for five, ten and fifteen musical instruments respectively if BT classifier is used.
DOI: 10.17762/ijritcc2321-8169.150713
Sequential Complexity as a Descriptor for Musical Similarity
We propose string compressibility as a descriptor of temporal structure in
audio, for the purpose of determining musical similarity. Our descriptors are
based on computing track-wise compression rates of quantised audio features,
using multiple temporal resolutions and quantisation granularities. To verify
that our descriptors capture musically relevant information, we incorporate our
descriptors into similarity rating prediction and song year prediction tasks.
We base our evaluation on a dataset of 15500 track excerpts of Western popular
music, for which we obtain 7800 web-sourced pairwise similarity ratings. To
assess the agreement among similarity ratings, we perform an evaluation under
controlled conditions, obtaining a rank correlation of 0.33 between intersected
sets of ratings. Combined with bag-of-features descriptors, we obtain
performance gains of 31.1% and 10.9% for similarity rating prediction and song
year prediction. For both tasks, analysis of selected descriptors reveals that
representing features at multiple time scales benefits prediction accuracy.Comment: 13 pages, 9 figures, 8 tables. Accepted versio
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