Download Robust multipich estimation for the analysis and manipulation of polyphonic musical signals
A method for the estimation of the multiple pitches of concurrent musical sounds is described. Experimental data comprised sung vowels and the whole pitch range of 26 musical instruments. Multipitch estimation was performed at the level of a single time frame for random pitch and sound source combinations. Note error rates for mixtures ranging from one to six simultaneous sounds were 2.1 %, 2.4 %, 3.8 %, 8.1 %, 12 %, and 18 %, respectively. In musical interval and chord identification tasks, the algorithm outperformed the average of ten trained musicians. Particular emphasis was laid on robustness in the presence of other sounds and noise. The algorithm is based on an iterative estimation and separation procedure and is able to resolve at least a couple of most prominent pitches even in ten sound polyphonies. Sounds that exhibit inharmonicities can be handled without problems, and the inharmonicity factor and spectral envelope of each sound is estimated along with the pitch. Examples are given of musical signal manipulations that become possible with the proposed method.
Download Algorithm for the separation of harmonic sounds with time-frequency smoothness constraint
A signal model is described which forces temporal and spectral smoothness of harmonic sounds. Smoothness refers to harmonic partials, the amplitudes of which are slowly-varying as a function of time and frequency. An algorithm is proposed for the estimation of the model parameters. The algorithm is utilized in a sound separation system, the robustness of which is increased by the smoothness constraints.
Download A Similarity Measure for Audio Query by Example Based on Perceptual Coding and Compression
Query by example for multimedia signals aims at automatic retrieval of samples from the media database similar to a userprovided example. This paper proposes a similarity measure for query by example of audio signals. The method first represents audio signals using perceptual audio coding and second estimates the similarity of two signals from the advantage gained by compressing the files together in comparison to compressing them individually. Signals which benefit most from compressing together are considered similar. The low bit rate perceptual audio coding preprocessing effectively retains perceptually important features while quantizing the signals so that identical codewords appear, allowing further inter-signal compression. The advantage of the proposed similarity measure is that it is parameter-free, thus it is easy to apply in wide range of tasks. Furthermore, users’ expectations do not affect the results like they do in parameter-laden algorithms. A comparison was made against the other query by example methods and simulation results reveal that the proposed method gives competitive results against the other methods.
Download Automatic alignment of music audio and lyrics
This paper proposes an algorithm for aligning singing in polyphonic music audio with textual lyrics. As preprocessing, the system uses a voice separation algorithm based on melody transcription and sinusoidal modeling. The alignment is based on a hidden Markov model speech recognizer where the acoustic model is adapted to singing voice. The textual input is preprocessed to create a language model consisting of a sequence of phonemes, pauses and possible instrumental breaks. Viterbi algorithm is used to align the audio features with the text. On a test set consisting of 17 commercial recordings, the system achieves an average absolute error of 1.40 seconds in aligning lines of the lyrics.
Download Music Dereverberation by Spectral Linear Prediction in Live Recordings
In this paper, we present our evaluations in using blind single channel dereverberation on music signals. The target material is heavily reverberated and dynamic range compressed polyphonic music from several genres. The applied dereverberation method is based on spectral subtraction regulated by a time-frequency domain linear predictive model. We present our results on enhancing music signal quality and automatic beat tracking accuracy with the proposed dereverberation method. Signal quality enhancement, measured by improvement in signal to distortion ratio, is achieved for both reverberant and dynamic range compressed signals. Moreover, the algorithm shows potential as a preprocessing method for music beat tracking.