[Anas Mahmoud]

كود :

   WithEvents TimerHour As New Timer With {
       .Interval = 1000,
       .Enabled = True}
   Dim lastHour As Integer = -1
   Private Sub TimerHour_Tick(sender As Object, e As EventArgs) Handles TimerHour.Tick
       If DateTime.Now.Hour <> lastHour And DateTime.Now.Minute = 0 Then
           lastHour = DateTime.Now.Hour
           My.Computer.Audio.Play("d:\h.wav")
       End If
   End Sub

https://stackoverflow.com/a/19292014/14137871