سلام
میتونی از این کلاس استفاده کنی ، از سایت MSDN گرفتم البته با کمی تغییرات
Imports System
Imports System.Windows.Forms
Imports System.Runtime.InteropServices
Public Class SoundControl
Inherits Form
Private Const APPCOMMAND_VOLUME_MUTE As Integer = &H80000
Private Const APPCOMMAND_VOLUME_UP As Integer = &HA0000
Private Const APPCOMMAND_VOLUME_DOWN As Integer = &H90000
Private Const WM_APPCOMMAND As Integer = &H319
<DllImport("user32.dll")> _
Public Shared Function SendMessageW(ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
End Function
Public Sub SoundMute()
SendMessageW(Me.Handle, WM_APPCOMMAND, Me.Handle, New IntPtr(APPCOMMAND_VOLUME_MUTE))
End Sub
Public Sub SoundInc()
SendMessageW(Me.Handle, WM_APPCOMMAND, Me.Handle, New IntPtr(APPCOMMAND_VOLUME_UP))
End Sub
Public Sub SoundDec()
SendMessageW(Me.Handle, WM_APPCOMMAND, Me.Handle, New IntPtr(APPCOMMAND_VOLUME_DOWN))
End Sub
End Class