Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

// note: DevicesNames must be created before calling this procedure 

uses mmsystem;

 procedure GetWaveOutDevices(DeviceNames: TStrings);
 var
   DNum: Integer;
   i: Integer;
   Caps: TWaveOutCapsA;
 begin
   DNum := waveOutGetNumDevs;  // Number of Devices 
  for i := 0 to DNum - 1 do     // Query Devicenames 
  begin
     waveOutGetDevCaps(i, @Caps, SizeOf(TWaveOutCapsA));
     DeviceNames.Add(string(Caps.szPname));
   end;
 end;


 procedure TForm1.Button1Click(Sender: TObject);
 begin
   GetWaveOutDevices(Listbox1.Items);
 end;