polyphony occurs when several meters are played simultaneously

We consider that the sinusoids with the frequencies of the partials of each note define a signal composed of approximately orthogonal components. So, our model will consider each piano note as a CDMA user. This means that multiple signals from different users are transmitted simultaneously after a spreading process that makes them approximately orthogonal signals. In this system, the communications signal is a code division multiple access (CDMA) signal. The audio signal to be analyzed will be considered to have certain similarities with the communications signal of a 3G mobile communications system. In this paper, we consider a different point of view. Marolt uses a partial tracking technique based on a combination of an auditory model and adaptive oscillator networks followed by a time-delay neural network to perform automatic transcription of polyphonic piano music.

Vincent and Plumbley propose an extraction technique based on Bayesian harmonic models. In the paper by Tolonand and Karjalainen, a multipitch analysis model for audio and speech signals is proposed with some basis on the human auditory model. Dixon uses heuristics in the context of the Short Time Fourier Transform (STFT) to find peaks in the power spectrum to define musical notes also tracking the detected peaks in consecutive audio segments is considered. propose a Bayesian approach to estimate notes and chords. In the contribution by Klapuri a multiple estimation method based on the iterative estimation of harmonic amplitudes and cancellation is presented.

In the paper by Goto, a multiple estimation method based on a MAP approach to detect melody and bass lines is described. The approach employed in this paper is rather different from other proposals that can be found in the literature. Therefore, the objective in this paper is to robustly determine the notes that sound simultaneously in each of the chords of a piano piece.

More precisely, we deal with the multiple fundamental frequency ( ) estimation problem in audio signals composed of piano chords. We are refering to the detection of the notes that sound simultaneously in each of the temporal segments in which the musical piece can be divided. In this paper, we deal with a main stage of automatic music transcription systems.

Polyphony occurs when several meters are played simultaneously