diff --git a/src/Discord.Net.Core/Entities/Messages/FileAttachment.cs b/src/Discord.Net.Core/Entities/Messages/FileAttachment.cs
index 7d7f6a4630..57bb8ba262 100644
--- a/src/Discord.Net.Core/Entities/Messages/FileAttachment.cs
+++ b/src/Discord.Net.Core/Entities/Messages/FileAttachment.cs
@@ -27,6 +27,16 @@ public struct FileAttachment : IDisposable
         /// </summary>
         public bool IsThumbnail { get; set; }
 
+        /// <summary>
+        ///     Gets or sets the duration of a voice message. <see langword="null"/> if the attachment is not a voice message.
+        /// </summary>
+        public double? DurationSeconds { get; set; }
+
+        /// <summary>
+        ///     Gets or sets bytearray representing a sampled waveform. <see langword="null"/> if the attachment is not a voice message.
+        /// </summary>
+        public byte[] Waveform { get; set; } 
+
 #pragma warning disable IDISP008
         /// <summary>
         ///     Gets the stream containing the file content.
@@ -44,7 +54,7 @@ public struct FileAttachment : IDisposable
         /// <param name="description">The description of the attachment.</param>
         /// <param name="isSpoiler">Whether or not the attachment is a spoiler.</param>
         /// <param name="isThumbnail">Whether or not this attachment should be a thumbnail for a media channel post.</param>
-        public FileAttachment(Stream stream, string fileName, string description = null, bool isSpoiler = false, bool isThumbnail = false)
+        public FileAttachment(Stream stream, string fileName, string description = null, bool isSpoiler = false, bool isThumbnail = false, double? durationSeconds = null, byte[] waveform = null)
         {
             _isDisposed = false;
             FileName = fileName;
@@ -57,6 +67,8 @@ public FileAttachment(Stream stream, string fileName, string description = null,
             }
             catch { }
             IsSpoiler = isSpoiler;
+            DurationSeconds = durationSeconds;
+            Waveform = waveform;
         }
 
         /// <summary>
@@ -91,7 +103,7 @@ public FileAttachment(Stream stream, string fileName, string description = null,
         /// <exception cref="FileNotFoundException">The file specified in <paramref name="path" /> was not found.
         /// </exception>
         /// <exception cref="IOException">An I/O error occurred while opening the file. </exception>
-        public FileAttachment(string path, string fileName = null, string description = null, bool isSpoiler = false, bool isThumbnail = false)
+        public FileAttachment(string path, string fileName = null, string description = null, bool isSpoiler = false, bool isThumbnail = false, double? durationSeconds = null, byte[] waveform = null)
         {
             _isDisposed = false;
             Stream = File.OpenRead(path);
@@ -99,6 +111,8 @@ public FileAttachment(string path, string fileName = null, string description =
             Description = description;
             IsSpoiler = isSpoiler;
             IsThumbnail = isThumbnail;
+            DurationSeconds = durationSeconds;
+            Waveform = waveform;
         }
 
         public void Dispose()
diff --git a/src/Discord.Net.Core/Entities/Messages/IAttachment.cs b/src/Discord.Net.Core/Entities/Messages/IAttachment.cs
index 591c9586bf..65bf93e087 100644
--- a/src/Discord.Net.Core/Entities/Messages/IAttachment.cs
+++ b/src/Discord.Net.Core/Entities/Messages/IAttachment.cs
@@ -76,6 +76,11 @@ public interface IAttachment : ISnowflakeEntity
         /// </summary>
         public string Waveform { get; }
 
+        /// <summary>
+        ///     Gets the bytearray representing a sampled waveform. <see langword="null"/> if the attachment is not a voice message.
+        /// </summary>
+        public byte[] WaveformBytes { get; }
+
         /// <summary>
         ///     Gets flags related to this to this attachment.
         /// </summary>
diff --git a/src/Discord.Net.Rest/API/Rest/UploadFileParams.cs b/src/Discord.Net.Rest/API/Rest/UploadFileParams.cs
index 49a8268d7b..c1e4309eed 100644
--- a/src/Discord.Net.Rest/API/Rest/UploadFileParams.cs
+++ b/src/Discord.Net.Rest/API/Rest/UploadFileParams.cs
@@ -1,6 +1,7 @@
 using Discord.Net.Converters;
 using Discord.Net.Rest;
 using Newtonsoft.Json;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -34,6 +35,9 @@ public IReadOnlyDictionary<string, object> ToDictionary()
         {
             var d = new Dictionary<string, object>();
 
+            if (Files.Any(x => x.Waveform is not null && x.DurationSeconds is not null))
+                Flags = Flags.GetValueOrDefault(MessageFlags.None) | MessageFlags.VoiceMessage;
+
             var payload = new Dictionary<string, object>();
             if (Content.IsSpecified)
                 payload["content"] = Content.Value;
@@ -71,7 +75,11 @@ public IReadOnlyDictionary<string, object> ToDictionary()
                 {
                     id = (ulong)n,
                     filename = filename,
-                    description = attachment.Description ?? Optional<string>.Unspecified
+                    description = attachment.Description ?? Optional<string>.Unspecified,
+                    duration_secs = attachment.DurationSeconds ?? Optional<double>.Unspecified,
+                    waveform = attachment.Waveform is null
+                        ? Optional<string>.Unspecified
+                        : Convert.ToBase64String(attachment.Waveform)
                 });
             }
 
diff --git a/src/Discord.Net.Rest/API/Rest/UploadInteractionFileParams.cs b/src/Discord.Net.Rest/API/Rest/UploadInteractionFileParams.cs
index 9ba1001644..dcdc7e65a8 100644
--- a/src/Discord.Net.Rest/API/Rest/UploadInteractionFileParams.cs
+++ b/src/Discord.Net.Rest/API/Rest/UploadInteractionFileParams.cs
@@ -44,6 +44,8 @@ public IReadOnlyDictionary<string, object> ToDictionary()
         {
             var d = new Dictionary<string, object>();
 
+            if (Files.Any(x => x.Waveform is not null && x.DurationSeconds is not null))
+                Flags = Flags.GetValueOrDefault(MessageFlags.None) | MessageFlags.VoiceMessage;
 
             var payload = new Dictionary<string, object>();
             payload["type"] = Type;
@@ -79,7 +81,11 @@ public IReadOnlyDictionary<string, object> ToDictionary()
                 {
                     id = (ulong)n,
                     filename = filename,
-                    description = attachment.Description ?? Optional<string>.Unspecified
+                    description = attachment.Description ?? Optional<string>.Unspecified,
+                    duration_secs = attachment.DurationSeconds ?? Optional<double>.Unspecified,
+                    waveform = attachment.Waveform is null
+                        ? Optional<string>.Unspecified
+                        : Convert.ToBase64String(attachment.Waveform)
                 });
             }
 
diff --git a/src/Discord.Net.Rest/API/Rest/UploadWebhookFileParams.cs b/src/Discord.Net.Rest/API/Rest/UploadWebhookFileParams.cs
index c62426670c..f33eecfb9d 100644
--- a/src/Discord.Net.Rest/API/Rest/UploadWebhookFileParams.cs
+++ b/src/Discord.Net.Rest/API/Rest/UploadWebhookFileParams.cs
@@ -1,8 +1,10 @@
 using Discord.Net.Converters;
 using Discord.Net.Rest;
 using Newtonsoft.Json;
+using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Text;
 
 namespace Discord.API.Rest
@@ -35,6 +37,9 @@ public IReadOnlyDictionary<string, object> ToDictionary()
         {
             var d = new Dictionary<string, object>();
 
+            if (Files.Any(x => x.Waveform is not null && x.DurationSeconds is not null))
+                Flags = Flags.GetValueOrDefault(MessageFlags.None) | MessageFlags.VoiceMessage;
+
             var payload = new Dictionary<string, object>();
             if (Content.IsSpecified)
                 payload["content"] = Content.Value;
@@ -76,7 +81,11 @@ public IReadOnlyDictionary<string, object> ToDictionary()
                 {
                     id = (ulong)n,
                     filename = filename,
-                    description = attachment.Description ?? Optional<string>.Unspecified
+                    description = attachment.Description ?? Optional<string>.Unspecified,
+                    duration_secs = attachment.DurationSeconds ?? Optional<double>.Unspecified,
+                    waveform = attachment.Waveform is null
+                        ? Optional<string>.Unspecified
+                        : Convert.ToBase64String(attachment.Waveform)
                 });
             }
 
diff --git a/src/Discord.Net.Rest/Entities/Messages/Attachment.cs b/src/Discord.Net.Rest/Entities/Messages/Attachment.cs
index 592b2a5f55..73906efe5e 100644
--- a/src/Discord.Net.Rest/Entities/Messages/Attachment.cs
+++ b/src/Discord.Net.Rest/Entities/Messages/Attachment.cs
@@ -1,5 +1,6 @@
 using Discord.Rest;
 using System;
+using System.Buffers.Text;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics;
@@ -35,6 +36,8 @@ public class Attachment : IAttachment
         /// <inheritdoc />
         public string Waveform { get; }
         /// <inheritdoc />
+        public byte[] WaveformBytes { get; }
+        /// <inheritdoc />
         public double? Duration { get; }
 
         /// <inheritdoc cref="IAttachment.ClipParticipants" />
@@ -69,6 +72,8 @@ internal Attachment(ulong id, string filename, string url, string proxyUrl, int
             Title = title;
             ClipParticipants = clipParticipants;
             ClipCreatedAt = clipCreatedAt;
+            if (waveform is not null)
+                WaveformBytes = Convert.FromBase64String(waveform);
         }
 
         internal static Attachment Create(Model model, BaseDiscordClient discord)