diff --git a/media/libeffects/data/audio_effects.conf b/media/libeffects/data/audio_effects.conf
index e6a7b37..b8fa487 100644
--- a/media/libeffects/data/audio_effects.conf
+++ b/media/libeffects/data/audio_effects.conf
@@ -1,5 +1,10 @@
 # List of effect libraries to load. Each library element must contain a "path" element
 # giving the full path of the library .so file.
+#    libraries {
+#        <lib name> {
+#          path <lib path>
+#        }
+#    }
 libraries {
   bundle {
     path /system/lib/soundfx/libbundlewrapper.so
@@ -10,6 +15,9 @@
   visualizer {
     path /system/lib/soundfx/libvisualizer.so
   }
+  pre_processing {
+    path /system/lib/soundfx/libaudiopreprocessing.so
+  }
 }
 
 # list of effects to load. Each effect element must contain a "library" and a "uuid" element.
@@ -17,6 +25,16 @@
 # "libraries" element.
 # The name of the effect element is indicative, only the value of the "uuid" element
 # designates the effect.
+# The uuid is the implementation specific UUID as specified by the effect vendor. This is not the
+# generic effect type UUID.
+#    effects {
+#        <fx name> {
+#            library <lib name>
+#            uuid <effect uuid>
+#        }
+#        ...
+#    }
+
 effects {
   bassboost {
     library bundle
@@ -54,4 +72,55 @@
     library visualizer
     uuid d069d9e0-8329-11df-9168-0002a5d5c51b
   }
+  agc {
+    library pre_processing
+    uuid aa8130e0-66fc-11e0-bad0-0002a5d5c51b
+  }
+  aec {
+    library pre_processing
+    uuid bb392ec0-8d4d-11e0-a896-0002a5d5c51b
+  }
+  ns {
+    library pre_processing
+    uuid c06c8400-8e06-11e0-9cb6-0002a5d5c51b
+  }
 }
+# Audio preprocessor configurations.
+# The pre processor configuration consists in a list of elements each describing
+# pre processor settings for a given input source. Valid input source names are:
+# "mic", "camcorder", "voice_recognition", "voice_communication"
+# Each input source element contains a list of effects elements. The name of the effect
+# element must be the name of one of the effects in the "effects" list of the file.
+# Each effect element may optionally contain a list of parameters and their
+# default value to apply when the pre processor effect is created.
+# A parameter is defined by a "param" element and a "value" element. Each of these elements
+# consists in one or more elements specifying a type followed by a value.
+# The types defined are: "int", "short", "float", "bool" and "string"
+# When both "param" and "value" are a single int, a simple form is allowed where just
+# the param and value pair is present in the parameter description
+#    pre_processing {
+#        <input source name> {
+#            <fx name> {
+#                <param 1 name> {
+#                    param {
+#                        int|short|float|bool|string <value>
+#                        [ int|short|float|bool|string <value> ]
+#                        ...
+#                    }
+#                    value {
+#                        int|short|float|bool|string <value>
+#                        [ int|short|float|bool|string <value> ]
+#                        ...
+#                    }
+#                }
+#                <param 2 name > {<param> <value>}
+#                ...
+#            }
+#            ...
+#        }
+#        ...
+#    }
+
+#
+# TODO: add default audio pre processor configurations after debug and tuning phase
+#