diff --git a/Sources/SoundpipeAudioKit/Generators/PhaseLockedVocoder.swift b/Sources/SoundpipeAudioKit/Generators/PhaseLockedVocoder.swift
index c2c1b54..c573ee2 100644
--- a/Sources/SoundpipeAudioKit/Generators/PhaseLockedVocoder.swift
+++ b/Sources/SoundpipeAudioKit/Generators/PhaseLockedVocoder.swift
@@ -65,6 +65,7 @@ public class PhaseLockedVocoder: Node {
     ///   - position: Position in time. When non-changing it will do a spectral freeze of a the current point in time.
     ///   - amplitude: Amplitude.
     ///   - pitchRatio: Pitch ratio. A value of. 1  normal, 2 is double speed, 0.5 is halfspeed, etc.
+    ///   - grainSize: Size (samples, pow 2) of the spectral freeze. Lower sizes – crisper sound when moving position.
     ///
     public init(
         file: AVAudioFile,