Linear and exponential
This patch demonstrates the sound of linear and exponential changes in pitch and amplitude.
In the left side of the patch, clicking on the button causes a linear change in pitch (which is to say an exponential change in frequency) from low A (MIDI key number 33, 55 Hz fundamental, three ledger lines below the grand staff) to high A (MIDI key number 81, 880 Hz, the ledger line above the grand staff). At the same time, it effects an immediate 10 ms rise in amplitude to -6 dB followed by about an 8-second diminuendo to -18 dB, followed by a much more precipitous dropoff to complete silence in the next four seconds; all these changes are specified linearly in dB, so they cause exponential changes in absolute amplitude.
On the right side of the patch, a phasor~ with a frequency of -1 Hz causes a linear downward ramp from 1 to 0 every second; that ramp is used to control amplitude (from 1 to 0) and frequency (from 1760 Hz to 220 Hz). Linear changes of frequency and amplitude cause a perceptual effect of logarithmic changes (inverse exponential change) in pitch and loudness.