function GetWaveVolume: DWord;
var Woc : TWaveOutCaps;
Volume : DWord;
begin
result:=0;
if WaveOutGetDevCaps(WAVE_MAPPER, @Woc, sizeof(Woc)) =
MMSYSERR_NOERROR then begin
if Woc.dwSupport and WAVECAPS_VOLUME = WAVECAPS_VOLUME then begin
WaveOutGetVolume(WAVE_MAPPER, @Volume);
Result := Volume;
end;
end;
end;

procedure SetWaveVolume(const AVolume: DWord);
var Woc : TWaveOutCaps;
begin
if WaveOutGetDevCaps(WAVE_MAPPER, @Woc, sizeof(Woc)) =
MMSYSERR_NOERROR then begin
if Woc.dwSupport and WAVECAPS_VOLUME = WAVECAPS_VOLUME then
WaveOutSetVolume(WAVE_MAPPER, AVolume);
end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
Beep;
end;

procedure TForm1.Button2Click(Sender: TObject);
var LeftVolume: Word;
RightVolume: Word;
begin
LeftVolume := StrToInt(Edit1.Text);
RightVolume := StrToInt(Edit2.Text);
SetWaveVolume(MakeLong(LeftVolume, RightVolume));
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
Caption := IntToStr(GetWaveVolume);
end;