Providing a method to calculate durations of notes being played by user

[Fatemeh Hayati]

Music contains of sounds and rests. The four main elements of music sound are as followed: 1- Duration, 2- Loudness (intensity), 3- Pitch, and 4-Tone Color. In this project we want to study on notes duration by using signal/speech processing. But we don’t know how we can calculate duration of each note and rest.
For this aim, environmental issues such as quality of microphone, volume of user, distance between user and microphone during the play, environment noise, and etc. affect our signal

[audioeng]

What you could try at first, is to
1. frame the music (with the frame size being approximately 1/2 the duration of the fastest note)
2. calculate ZCR (or thresholded ZCR) and frame power or AMDF as described in the book
3. when you plot these signals, under a plot of the music, you will most likely see the gaps in the music show up in the two plots, very obviously

That's good for simple music, but in more complex music, one instrument might be playing while another instrument has a rest.
Therefore I would split the audio into a number of bands (use multiple passband filters). Then get ZCR and AMDF for each band separately.

The ZCR also doesn't work too well with background noise. But you can get around that by using the passband method.

It will give you duration.

For musical note, try using the LTP code shown in the book... most likely it will give you the fundamental frequency but it may be 2x or 0.5x the actual musical note (or some other relationship that's determined by the instrument type).

If you want something more mathematical, more complex, but potentially higher performance, try principal component analysis (PCA) or independent component analysis (ICA). These should (in theory, and if set up right), allow you to pick out individual instruments and track them.

Best wishes in your work - please report back how you got on (you can even post code here if it works)

On Saturday, August 25, 2012 11:27:07 PM UTC+8, Fatemeh Hayati wrote:

Music contains of sounds and rests. The four main elements of music sound are as followed: 1- Duration, 2- Loudness (intensity), 3- Pitch, and 4-Tone Colour. In this project we want to study on notes duration by using signal/speech processing. But we don’t know how we can calculate duration of each note and rest.