procedure GetWaveInDevices(DeviceNames: TStrings);
var
 DNum: integer;
 i:    integer;
 Caps: TWaveInCaps;
begin
 DNum := waveInGetNumDevs; // Number of Devices
 for i := 0 to DNum - 1 do // Query Devicenames
 begin
   waveInGetDevCaps(i, @Caps, SizeOf(TWaveInCaps));
   DeviceNames.Add(Caps.szPname);
 end;
end;

procedure GetWaveOutDevices(DeviceNames: TStrings);
var
 DNum: integer;
 i:    integer;
 Caps: TWaveOutCaps;

 pEnumerator: IMMDeviceEnumerator;
 pCollection: IMMDeviceCollection;
 pEndPoint: IMMDevice;
 hr: HRESULT;
 mask: DWORD;
 count: Cardinal;
 friendlyName: string;
 pProps: IPropertyStore;
 varName: PROPVARIANT;
begin
 if Win32MajorVersion < 6 then
 begin
   DNum := waveOutGetNumDevs; // Number of Devices
   for i := 0 to DNum - 1 do // Query Devicenames
   begin
     waveOutGetDevCaps(i, @Caps, SizeOf(TWaveOutCaps));
     DeviceNames.Add(Caps.szPname);
   end;
 end
 else
 begin
   HR := CoCreateInstance(CLASS_IMMDeviceEnumerator, nil, CLSCTX_INPROC_SERVER,
     IID_IMMDeviceEnumerator, pEnumerator);

   // get the endpoint collection
   mask := DEVICE_STATE_ACTIVE;
   hr := pEnumerator.EnumAudioEndpoints(eRender, mask, pCollection);

   // get the size of the collection
   count := 0;
   hr := pCollection.GetCount(count);

   for i := 0 to  (count - 1) do
   begin
       // get the endpoint
       hr := pCollection.Item(i, pEndPoint);

       // get the human readable name
       hr := pEndPoint.OpenPropertyStore(STGM_READ, pProps);
       PropVariantInit(varName);
       hr := pProps.GetValue(PKEY_Device_FriendlyName, varName);
       friendlyName := string(varName.pwszVal);
       DeviceNames.Add(friendlyName);
       PropVariantClear(@varName);
   end;
 end;
end;