The difference comes from whether we considering a verb or a noun; the action that resulted in something, or the thing itself. It does get a bit more complicated because we're using these constructs as modifiers
a high-pitched voice
his voice had a surprisingly high pitch
but to focus just on the noun/verb concept:
I can choose the tone of my voice, I can choose a pitch (noun). I can pitch (verb) my voice.
When we are using the word pitch as a verb its past tense is pitched. So describing the sound we can say
Her voice was high pitched
we are hearing the result of a speaker pitching their voice.
Similarly snow can be a noun or a verb. We can say
Snow (noun) has fallen.
It has snowed.
Note that snow in this usage is an impersonal verb, there is no actual subject in the sentence; it is a kind of place holder.
However (as Peter Shor has observed) there is another way in which the -ed may used, as a direct addition to a noun. Examples:
These are pseudo-participials, which are derived from nouns. I refer to this question in our sister site at the quotation from Downing and Locke, mentioned there.
Such pseudo-participials are often modiﬁed, as the modiﬁcation
represents some non-essential feature. We don’t say *a leaved plant,
*a haired girl, because plants normally have leaves and girls have hair. Not all leaves are big and not all girls’ hair is dark, however,
allowing the formation of big-leaved and dark-haired: a dark-haired
girl. In a camera’ed bystander, by contrast, no modiﬁer is needed
because carrying a camera is not an essential feature of a bystander.