diff --git a/docs/microbit_micropython_api.rst b/docs/microbit_micropython_api.rst
index 19362fdac..93c2400b7 100644
--- a/docs/microbit_micropython_api.rst
+++ b/docs/microbit_micropython_api.rst
@@ -108,6 +108,8 @@ The Microphone is accessed via the `microphone` object::
     set_threshold(128)
     # Returns a representation of the sound pressure level in the range 0 to 255.
     sound_level()
+    # Returns a representation of the sound pressure level in decibels (dB).
+    sound_level_db()
 
 Pins
 ----
diff --git a/docs/microphone.rst b/docs/microphone.rst
index 88a847031..f26a68e0e 100644
--- a/docs/microphone.rst
+++ b/docs/microphone.rst
@@ -91,6 +91,10 @@ Functions
 
     :return: A representation of the sound pressure level in the range 0 to 255.
 
+.. py:function:: sound_level_db()
+
+    :return: A representation of the sound pressure level in decibels (dB)
+        in the range of 52.0 to 110.0 dB.
 
 Example
 =======