Const SND_FILENAME As Integer = &H20000
Declare Function PlaySound Lib "winmm.dll" Alias "PlaySoundA" (ByVal lpszName _
  As String, ByVal hModule As Int32, ByVal dwFlags As Int32) As Int32
'// ...
Dim f As String = System.Environment.GetEnvironmentVariable("SYSTEMROOT") + _
  "\media\tada.wav"
Me.PlaySound(f, 0, SND_FILENAME)