system
Given the following post, respond as if you're commenting on Reddit:
human
How long a period of time has to pass between two clicks for the human ear to be able to distinguish between them rather than hear them as a single click?

Thank you.
gpt
Depending on the characteristics of the clicks, the usual threshold is 2 milliseconds (Hirsh, 1959; Patterson & Green 1970; both in JASA). It takes usually 15 to 20ms to tell what click comes first if the clicks differ by some property (amplitude, frequency, etc.)