This assignment is to make a movie-soundtrack-style foghorn sound. Your successful patch should sound like this.

To make the patch:

• Using a phasor~ and a table lookup (non-interpolating), make a signal that switches between 70.7 and 50 (for example. That ratio is about the square root or 2, which makes a musical tritone), going between the two with an overall period of 5 seconds. (The table only needs two values in it. The phasor~ output should be adjusted to have a range from 0 to 2.)
• Using that as the frequency for a second phasor~ object, and adjust that phasor's range to 1 to 301 (for example if it's a 303-point table), and use that as an index to a second table that holds an audio waveform. You can draw the waveform by hand and/or record something into it.
• Make a second frequency signal about 1/3 Hz. higher (just add the value to the output of the frequency table), and use it as the frequency for a second audio waveform lookup similar to the previous one.
• Add the two detuned audio waveforms and apply an amplitude control to the sum to allow turning the sound on and off. Make separate message boxes to turn the output sound on and off. When 'ON' the amplitude should be reasonable (say in the range 0.1 to 0.2).
• Test it to see that when you re-start Pd and reload the patch, all you have to do to hear the sound is turn on DSP and to click the "on" message box.

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