Link to the Sound File
The two channel piece is created by sonifying a time series of the monthly number of sunspots recorded from Zurich and another time series that measured the annual changes in the earth's rotation (in day length sec*10**-5)
Here are the datafiles: Number of Sunspots, Annual changes in the earth's rotation.
Here is the code: m220a-DataReader.ck, m220a-Duo.ck, m220a-Player.ck.
Homework Questions:
(1) Why are the values for gain squared?
I believe the squaring is somehow related to the perception of sound by human beings. Humans perceive sound intensity differences in a non-linear fashion i.e for lower intensities our ears are more sensitive to intensity changes and at higher intensities our ears are less sensitive to intensity changes thus this non-linear mapping ensures that the lower intensities are squished together and the higher intensities are moved away from each other
(2) Why use MIDI keynums for the freq values?
I believe using MIDI keynums ensure that the frequencies do not get squished into a small range for the given data . MIDI keynums ensure that the frequencies change in a log fashion thus covering a larger range
(3) What happens if the 100 ms update rate is increased or decreased significantly?
Increasing the update rate we hear the sound is played slower and if the update rate is reduced we hear the sound played faster