diff --git a/content/media/AudioNodeEngine.cpp b/content/media/AudioNodeEngine.cpp
index e87e1abf9212..b0a0fa78699c 100644
--- a/content/media/AudioNodeEngine.cpp
+++ b/content/media/AudioNodeEngine.cpp
@@ -125,6 +125,19 @@ BufferComplexMultiply(const float* aInput,
   }
 }
 
+float
+AudioBufferPeakValue(const float *aInput, uint32_t aSize)
+{
+  float max = 0.0f;
+  for (uint32_t i = 0; i < aSize; i++) {
+    float mag = fabs(aInput[i]);
+    if (mag > max) {
+      max = mag;
+    }
+  }
+  return max;
+}
+
 void
 AudioBlockCopyChannelWithScale(const float aInput[WEBAUDIO_BLOCK_SIZE],
                                const float aScale[WEBAUDIO_BLOCK_SIZE],
diff --git a/content/media/AudioNodeEngine.h b/content/media/AudioNodeEngine.h
index ca0614882eed..ad51fc87d473 100644
--- a/content/media/AudioNodeEngine.h
+++ b/content/media/AudioNodeEngine.h
@@ -134,6 +134,11 @@ void BufferComplexMultiply(const float* aInput,
                            float* aOutput,
                            uint32_t aSize);
 
+/**
+ * Vector maximum element magnitude ( max(abs(aInput)) ).
+ */
+float AudioBufferPeakValue(const float* aInput, uint32_t aSize);
+
 /**
  * In place gain. aScale == 1.0f should be optimized.
  */