diff --git a/include/system/audio.h b/include/system/audio.h
index 2424baf..afd7176 100644
--- a/include/system/audio.h
+++ b/include/system/audio.h
@@ -114,11 +114,13 @@
 
 /* PCM sub formats */
 typedef enum {
+    /* All of these are in native byte order */
     AUDIO_FORMAT_PCM_SUB_16_BIT          = 0x1, /* DO NOT CHANGE - PCM signed 16 bits */
     AUDIO_FORMAT_PCM_SUB_8_BIT           = 0x2, /* DO NOT CHANGE - PCM unsigned 8 bits */
     AUDIO_FORMAT_PCM_SUB_32_BIT          = 0x3, /* PCM signed .31 fixed point */
     AUDIO_FORMAT_PCM_SUB_8_24_BIT        = 0x4, /* PCM signed 7.24 fixed point */
     AUDIO_FORMAT_PCM_SUB_FLOAT           = 0x5, /* PCM single-precision floating point */
+    AUDIO_FORMAT_PCM_SUB_24_BIT_PACKED   = 0x6, /* PCM signed .23 fixed point packed in 3 bytes */
 } audio_format_pcm_sub_fmt_t;
 
 /* The audio_format_*_sub_fmt_t declarations are not currently used */
@@ -183,6 +185,8 @@
                                         AUDIO_FORMAT_PCM_SUB_8_24_BIT),
     AUDIO_FORMAT_PCM_FLOAT           = (AUDIO_FORMAT_PCM |
                                         AUDIO_FORMAT_PCM_SUB_FLOAT),
+    AUDIO_FORMAT_PCM_24_BIT_PACKED   = (AUDIO_FORMAT_PCM |
+                                        AUDIO_FORMAT_PCM_SUB_24_BIT_PACKED),
 } audio_format_t;
 
 enum {