diff --git a/audio/7.0/types.hal b/audio/7.0/types.hal
index 1ae7bad..2d42129 100644
--- a/audio/7.0/types.hal
+++ b/audio/7.0/types.hal
@@ -44,8 +44,10 @@
  * A substitute for POSIX timespec.
  */
 struct TimeSpec {
-    uint64_t tvSec;   // seconds
-    uint64_t tvNSec;  // nanoseconds
+    /** Seconds. */
+    uint64_t tvSec;
+    /** Nanoseconds. */
+    uint64_t tvNSec;
 };
 
 struct ParameterValue {
@@ -85,8 +87,10 @@
  * Used by streams opened in mmap mode.
  */
 struct MmapPosition {
-    int64_t  timeNanoseconds; // time stamp in ns, CLOCK_MONOTONIC
-    int32_t  positionFrames;  // increasing 32 bit frame count reset when IStream.stop() is called
+    /** Timestamp in ns, CLOCK_MONOTONIC. */
+    int64_t  timeNanoseconds;
+    /** Increasing 32 bit frame count reset when IStream.stop() is called. */
+    int32_t  positionFrames;
 };
 
 /**
@@ -128,9 +132,12 @@
  */
 @export(name="audio_microphone_channel_mapping_t", value_prefix="AUDIO_MICROPHONE_CHANNEL_MAPPING_")
 enum AudioMicrophoneChannelMapping : uint32_t {
-    UNUSED      = 0, /* Channel not used */
-    DIRECT      = 1, /* Channel used and signal not processed */
-    PROCESSED   = 2, /* Channel used and signal has some processing */
+    /** Channel not used. */
+    UNUSED      = 0,
+    /** Channel used and signal not processed. */
+    DIRECT      = 1,
+    /** Channel used and signal has some processing. */
+    PROCESSED   = 2,
 };
 
 /**
@@ -269,7 +276,6 @@
     // frameworks/base/media/java/android/media/AudioTrack.java
     /**
      * Disable any Dual Mono presentation effect.
-     *
      */
     OFF = 0,
     /**
diff --git a/audio/common/7.0/types.hal b/audio/common/7.0/types.hal
index 2da9815..ed56c73 100644
--- a/audio/common/7.0/types.hal
+++ b/audio/common/7.0/types.hal
@@ -332,14 +332,22 @@
  * A gain stage is always attached to an audio port.
  */
 struct AudioGain {
-    vec<AudioGainMode> mode; // modes of operation
-    AudioChannelMask channelMask; // channels which gain can be controlled
-    int32_t minValue;     // minimum gain value in millibels
-    int32_t maxValue;     // maximum gain value in millibels
-    int32_t defaultValue; // default gain value in millibels
-    uint32_t stepValue;   // gain step in millibels
-    uint32_t minRampMs;   // minimum ramp duration in ms
-    uint32_t maxRampMs;   // maximum ramp duration in ms
+    /** Modes of operation. */
+    vec<AudioGainMode> mode;
+    /** Channels which gain can be controlled. */
+    AudioChannelMask channelMask;
+    /** Minimum gain value in millibels. */
+    int32_t minValue;
+    /** Maximum gain value in millibels. */
+    int32_t maxValue;
+    /** Default gain value in millibels. */
+    int32_t defaultValue;
+    /** Gain step in millibels. */
+    uint32_t stepValue;
+    /** Ramp duration in ms. */
+    uint32_t minRampMs;
+    /** Maximum ramp duration in ms. */
+    uint32_t maxRampMs;
 };
 
 /**
@@ -347,16 +355,20 @@
  * given port.
  */
 struct AudioGainConfig {
-    int32_t index;  // index of the corresponding AudioGain in AudioPort.gains
-    vec<AudioGainMode> mode; // modes of operation
-    AudioChannelMask channelMask;  // channels which gain value follows
+    /** Index of the corresponding AudioGain in AudioPort.gains. */
+    int32_t index;
+    /** Modes of operation. */
+    vec<AudioGainMode> mode;
+    /** Channels which gain value follows. */
+    AudioChannelMask channelMask;
     /**
      * Gain values in millibels for each channel ordered from LSb to MSb in
      * channel mask. The number of values is 1 in joint mode or
      * the number of channels in the channel mask.
      */
     vec<int32_t> values;
-    uint32_t rampDurationMs;  // ramp duration in ms
+    /** Ramp duration in ms. */
+    uint32_t rampDurationMs;
 };
 
 
diff --git a/audio/effect/7.0/types.hal b/audio/effect/7.0/types.hal
index fe4ee51..b0a0709 100644
--- a/audio/effect/7.0/types.hal
+++ b/audio/effect/7.0/types.hal
@@ -202,16 +202,26 @@
  * enumeration of the effect engines present in a library.
  */
 struct EffectDescriptor {
-    Uuid type;                   // UUID of to the OpenSL ES interface implemented
-                                 // by this effect
-    Uuid uuid;                   // UUID for this particular implementation
-    bitfield<EffectFlags> flags; // effect engine capabilities/requirements flags
-    uint16_t cpuLoad;            // CPU load indication expressed in 0.1 MIPS units
-                                 // as estimated on an ARM9E core (ARMv5TE) with 0 WS
-    uint16_t memoryUsage;        // data memory usage expressed in KB and includes
-                                 // only dynamically allocated memory
-    uint8_t[64] name;            // human readable effect name
-    uint8_t[64] implementor;     // human readable effect implementor name
+    /** UUID of to the OpenSL ES interface implemented by this effect. */
+    Uuid type;
+    /** UUID for this particular implementation. */
+    Uuid uuid;
+    /** Effect engine capabilities/requirements flags. */
+    bitfield<EffectFlags> flags;
+    /**
+     * CPU load indication expressed in 0.1 MIPS units as estimated on
+     * an ARM9E core (ARMv5TE) with 0 WS.
+     */
+    uint16_t cpuLoad;
+    /**
+     * Data memory usage expressed in KB and includes only dynamically
+     * allocated memory.
+     */
+    uint16_t memoryUsage;
+    /** Human readable effect name. */
+    uint8_t[64] name;
+    /** Human readable effect implementor name. */
+    uint8_t[64] implementor;
 };
 
 /**
@@ -242,11 +252,16 @@
  */
 @export(name="", value_prefix="EFFECT_CONFIG_")
 enum EffectConfigParameters : int32_t {
-    BUFFER = 0x0001,    // buffer field
-    SMP_RATE = 0x0002,  // samplingRate
-    CHANNELS = 0x0004,  // channels
-    FORMAT = 0x0008,    // format
-    ACC_MODE = 0x0010,  // accessMode
+    /** Buffer field. */
+    BUFFER = 0x0001,
+    /** Sampling rate. */
+    SMP_RATE = 0x0002,
+    /** Channels. */
+    CHANNELS = 0x0004,
+    /** Format. */
+    FORMAT = 0x0008,
+    /** Access mode. */
+    ACC_MODE = 0x0010,
     // Note that the 2.0 ALL have been moved to an helper function
 };
 
@@ -270,21 +285,23 @@
 
 @export(name="effect_feature_e", value_prefix="EFFECT_FEATURE_")
 enum EffectFeature : int32_t {
-    AUX_CHANNELS, // supports auxiliary channels
-                  // (e.g. dual mic noise suppressor)
+    /** Supports auxiliary channels (e.g. dual mic noise suppressor). */
+    AUX_CHANNELS,
     CNT
 };
 
 struct EffectAuxChannelsConfig {
-    vec<AudioChannelMask> mainChannels;  // channel mask for main channels
-    vec<AudioChannelMask> auxChannels;   // channel mask for auxiliary channels
+    /** Channel mask for main channels. */
+    vec<AudioChannelMask> mainChannels;
+    /** Channel mask for auxiliary channels. */
+    vec<AudioChannelMask> auxChannels;
 };
 
 struct EffectOffloadParameter {
-    bool isOffload;          // true if the playback thread the effect
-                             // is attached to is offloaded
-    AudioIoHandle ioHandle;  // io handle of the playback thread
-                             // the effect is attached to
+    /** True if the playback thread the effect is attached to is offloaded. */
+    bool isOffload;
+    /** I/O handle of the playback thread the effect is attached to. */
+    AudioIoHandle ioHandle;
 };
 
 /**