diff --git a/dev-docs/adunit-reference.md b/dev-docs/adunit-reference.md
index 9f3c4af33b..2ccd788cc5 100644
--- a/dev-docs/adunit-reference.md
+++ b/dev-docs/adunit-reference.md
@@ -11,7 +11,7 @@ sidebarType: 1
 
 The ad unit object is where you configure what kinds of ads you will show in a given ad slot on your page, including:
 
-* Allowed media types (e.g., banner, native, and/or video)
+* Allowed media types (e.g., banner, native, video and/or audio)
 * Allowed sizes
 * AdUnit-specific first party data
 
@@ -74,6 +74,7 @@ See the table below for the list of properties in the `mediaTypes` object of the
 | [`banner`](#adUnit.mediaTypes.banner) | At least one of the `banner`, `native`, or `video` objects are required. | Object | Defines properties of a banner ad. For examples, see [`adUnit.mediaTypes.banner`](#adUnit.mediaTypes.banner). |
 | [`native`](#adUnit.mediaTypes.native) | At least one of the `banner`, `native`, or `video` objects are required. | Object | Defines properties of a native ad. For properties, see [`adUnit.mediaTypes.native`](#adUnit.mediaTypes.native). |
 | [`video`](#adUnit.mediaTypes.video) | At least one of the `banner`, `native`, or `video` objects are required. | Object | Defines properties of a video ad. For examples, see [`adUnit.mediaTypes.video`](#adUnit.mediaTypes.video). |
+| [`audio`](#adUnit.mediaTypes.audio) | At least one of the `banner`, `native`, `video` or `audio` objects are required. | Object | Defines properties of a audio ad. For examples, see [`adUnit.mediaTypes.audio`](#adUnit.mediaTypes.audio). |
 
 <a name="adUnit.mediaTypes.banner"></a>
 
@@ -160,6 +161,27 @@ When using the Video Module, the mediaTypes.video properties get filled out auto
 | `adServer.baseAdTagUrl` | required if `adServer.params` is not defined | string | Your AdServer Ad Tag. The targeting params of the winning bid will be appended. |
 | `adServer.params` | required if `adServer.baseAdTagUrl` is not defined | object | Querystring parameters that will be used to construct the video ad tag URL. |
 
+<a name="adUnit.mediaTypes.audio"></a>
+
+#### adUnit.mediaTypes.audio
+
+{: .table .table-bordered .table-striped }
+| Name | Scope | Type | Description |
+|------------------+-------------+------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `context` | Recommended | String | The audio context. Defaults to 'instream'. |
+| `useCacheKey` | Optional | Boolean | Defaults to `false`. If set to `true`, the cache url defined in the global options will also be used for outstream responses. |
+| `api` | Recommended | Array[Integer] | List of supported API frameworks for this impression. If an API is not explicitly listed, it is assumed not to be supported. For list, see [OpenRTB 2.5 spec][openRTB]. If your player supports [Open Measurement][OpenMeasurement], **recommended** to set `7` for OMID-1|
+| `mimes` | Recommended | Array[String] | Content MIME types supported, e.g. `"audio/mp3"`. **Required by OpenRTB when using [Prebid Server][pbServer]**. |
+| `minduration` | Recommended | Integer | Minimum audio ad duration in seconds, see [OpenRTB 2.5 spec][openRTB]. |
+| `maxduration` | Recommended | Integer | Maximum audio ad duration in seconds, see [OpenRTB 2.5 spec][openRTB]. |
+| `startdelay` | Recommended | Integer | Indicates the start delay in seconds, see [OpenRTB 2.5 spec][openRTB]. |
+| `minbitrate` | Optional | Integer | Minimum bit rate in Kbps., see [OpenRTB 2.5 spec][openRTB]. |
+| `maxbitrate` | Optional | Integer | Maximum bit rate in Kbps., see [OpenRTB 2.5 spec][openRTB]. |
+| `delivery` | Optional | Array[Integer] | Supported delivery methods (e.g., streaming, progressive), see [OpenRTB 2.5 spec][openRTB]. |
+| `companionad` | Optional | Array[Object] | Array of Banner objects (Section 3.2.6) if companion ads are available, see [OpenRTB 2.5 spec][openRTB]. |
+| `feed` | Optional | Integer | Type of audio feed, see [OpenRTB 2.5 spec][openRTB]. |
+| `nvol` | Optional | Integer | Volume normalization mode, see [OpenRTB 2.5 spec][openRTB]. |
+
 ## Examples
 
 * [Banner](#adUnit-banner-example)
diff --git a/dev-docs/bidder-adaptor.md b/dev-docs/bidder-adaptor.md
index e6f682b11f..9af41e2794 100644
--- a/dev-docs/bidder-adaptor.md
+++ b/dev-docs/bidder-adaptor.md
@@ -221,7 +221,7 @@ A high level example of the structure:
 import * as utils from 'src/utils';
 import { registerBidder } from 'src/adapters/bidderFactory';
 import { config } from 'src/config';
-import {BANNER, VIDEO, NATIVE} from 'src/mediaTypes.ts';
+import {BANNER, VIDEO, NATIVE, AUDIO} from 'src/mediaTypes.ts';
 const BIDDER_CODE = 'example';
 export const spec = {
     code: BIDDER_CODE,
@@ -238,7 +238,7 @@ export const spec = {
     onSetTargeting: function(bid) {},
     onBidderError: function({ error, bidderRequest }) {},
     onAdRenderSucceeded: function(bid) {},
-    supportedMediaTypes: [BANNER, VIDEO, NATIVE]
+    supportedMediaTypes: [BANNER, VIDEO, NATIVE, AUDIO]
 }
 registerBidder(spec);