Describe how a sound FX pitch keeps the length

Ranges of Pitch, Gain and the EQ bands follow #312 #313 #314, and the EQ is now called 5-Band-EQ.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Sounds.md

@@ -98,12 +98,20 @@ Input and the Output once each; their pins carry sound and fit nothing but each
 | Node | What it does |
 | --- | --- |
 | **Gain** | Louder or quieter, in dB (`Gain (dB)`): 0 leaves it alone, -6 is about half as loud, +6 twice. Above 0 the sound can clip. |
-| **Pitch** | Higher or lower, in semitones (12 is an octave). It is the speed the sound is played at, so a higher sound is also shorter, and it applies to the **whole** sound wherever the node sits. |
-| **EQ** | Five bands in dB: 80 Hz and 12 kHz as shelves, 250 Hz, 1 kHz and 4 kHz as peaks. A band at 0 does nothing. |
+| **Pitch** | Higher or lower, in semitones (12 is an octave, 0.5 a quarter tone). The sound **keeps its length**, and the pitch applies to the **whole** sound wherever the node sits. |
+| **5-Band-EQ** | Five bands in dB: 80 Hz and 12 kHz as shelves, 250 Hz, 1 kHz and 4 kHz as peaks. A band at 0 does nothing. |
 
 Every number of these nodes is an **input**: typed in while nothing is connected, or fed from a
-parameter of the Input. Each is held to its range (Gain -60 to +24 dB, Pitch and the EQ bands
--24 to +24), whichever way the value arrives.
+parameter of the Input. Each is held to its range (Gain -120 to +24 dB, Pitch -64 to +64, the EQ
+bands -60 to +24 dB), whichever way the value arrives.
+
+**How Pitch keeps the length.** The sound is first read faster or slower, which sets the pitch,
+and then stretched back to its length by WSOLA: short frames (40 ms) laid over each other, each
+moved a little so a tone carries on without a jump. The pitched copy is worked out when a voice
+starts — about 15 ms per second of a 48 kHz channel — and kept for the next voice at the same pitch
+(the last 32 are kept). A looping sound is stretched across its seam, so the loop stays clean.
+Far from 0 it gets rough: a pitch that lands above half the sample rate folds back down, and a
+very low one smears, since a frame is shorter than one period of what is left.
 
 **It is a line, not a mixer.** An input takes one edge, so the way from Input to Output never forks;
 a node hanging off the line is simply not heard. A node on the way with nothing coming in, or a