How to make a call and play a sound clip

I believe this will require the TAPI (Telephone API) library to dial the phone in conjunction with the multimedia dll (or direct x) to play the sound.

TAPI is not officially part of .NET as far as I know, but you can use the c:\windows\system32\tapi3.dll which is a COM object that will let you communicate with the telephone api.  Just add it as a reference to your project.

To program TAPI, check out this article  to get you started.

Sounds can be played easily through winmm.dll.  Just declare it with DllImport

 // PlaySound()
using System.Runtime.InteropServices; 

[DllImport("winmm.dll", SetLastError=true,                                 CallingConvention=CallingConvention.Winapi)]
 static extern bool PlaySound(
                string pszSound,
                IntPtr hMod,
                SoundFlags sf );