public static void Main() { // NOTE: // When used in trial mode, the library imposes some restrictions. // Please visit http://bitmiracle.com/pdf-library/trial-restrictions.aspx // for more information. const string PathToFile = "RichMediaAnnotations.pdf"; using (var pdf = new PdfDocument()) { PdfPage page = pdf.Pages[0]; var bounds = new PdfRectangle(10, 50, 200, 100); PdfFileSpecification sound = pdf.CreateFileAttachment(@"..\Sample Data\sound.mp3"); PdfRichMediaAnnotation annot = page.AddRichMediaAnnotation(bounds, sound, PdfRichMediaContentType.Sound); annot.Activation.ActivationMode = PdfRichMediaActivationMode.OnPageOpen; pdf.Save(PathToFile); } Console.WriteLine($"The output is located in {Environment.CurrentDirectory}"); }