Как изменить уровень громкости микрофона?

uses 
  MMSystem; 
 
// Set the volume for the microphone 
 
function SetMicrophoneVolume(bValue: Word): Boolean; 
var                          {0..65535} 
  hMix: HMIXER; 
  mxlc: MIXERLINECONTROLS; 
  mxcd: TMIXERCONTROLDETAILS; 
  vol: TMIXERCONTROLDETAILS_UNSIGNED; 
  mxc: MIXERCONTROL; 
  mxl: TMixerLine; 
  intRet: Integer; 
  nMixerDevs: Integer; 
begin 
  // Check if Mixer is available 
  nMixerDevs := mixerGetNumDevs(); 
  if (nMixerDevs < 1) then 
  begin 
    Exit; 
  end; 
 
  // open the mixer 
  intRet := mixerOpen(@hMix, 0, 0, 0, 0); 
  if intRet = MMSYSERR_NOERROR then 
  begin 
    mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE; 
    mxl.cbStruct := SizeOf(mxl); 
 
    // get line info 
    intRet := mixerGetLineInfo(hMix, @mxl, MIXER_GETLINEINFOF_COMPONENTTYPE); 
 
    if intRet = MMSYSERR_NOERROR then 
    begin 
      ZeroMemory(@mxlc, SizeOf(mxlc)); 
      mxlc.cbStruct := SizeOf(mxlc); 
      mxlc.dwLineID := mxl.dwLineID; 
      mxlc.dwControlType := MIXERCONTROL_CONTROLTYPE_VOLUME; 
      mxlc.cControls := 1; 
      mxlc.cbmxctrl := SizeOf(mxc); 
 
      mxlc.pamxctrl := @mxc; 
      intRet := mixerGetLineControls(hMix, @mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE); 
 
      if intRet = MMSYSERR_NOERROR then 
      begin 
      { 
       // Microphone Name 
          Label1.Caption := mxlc.pamxctrl.szName; 
 
        // Min/Max Volume 
        Label2.Caption := IntToStr(mxc.Bounds.dwMinimum) + '->' + IntToStr(mxc.Bounds.dwMaximum); 
      } 
        ZeroMemory(@mxcd, SizeOf(mxcd)); 
        mxcd.dwControlID := mxc.dwControlID; 
        mxcd.cbStruct := SizeOf(mxcd); 
        mxcd.cMultipleItems := 0; 
        mxcd.cbDetails := SizeOf(Vol); 
        mxcd.paDetails := @vol; 
        mxcd.cChannels := 1; 
 
        // vol.dwValue := mxlc.pamxctrl.Bounds.lMinimum; Set min. Volume / Minimum setzen 
        // vol.dwValue := mxlc.pamxctrl.Bounds.lMaximum; Set max. Volume / Maximum setzen 
        vol.dwValue := bValue; 
 
        intRet := mixerSetControlDetails(hMix, @mxcd, 
          MIXER_SETCONTROLDETAILSF_VALUE); 
        if intRet <> MMSYSERR_NOERROR then 
          ShowMessage('SetControlDetails Error'); 
      end 
      else 
        ShowMessage('GetLineInfo Error'); 
    end; 
    intRet := mixerClose(hMix); 
  end; 
end; 
 
procedure TForm1.Button1Click(Sender: TObject); 
begin 
  SetMicrophoneVolume(30000); 
end; 
 
{********************************************************} 
 
 
// Enable/disable "Mute Microphone Volume" 
 
function SetMicrophoneVolumeMute(bMute: Boolean): Boolean; 
var 
  hMix: HMIXER; 
  mxlc: MIXERLINECONTROLS; 
  mxcd: TMIXERCONTROLDETAILS; 
  vol: TMIXERCONTROLDETAILS_UNSIGNED; 
  mxc: MIXERCONTROL; 
  mxl: TMixerLine; 
  intRet: Integer; 
  nMixerDevs: Integer; 
  mcdMute: MIXERCONTROLDETAILS_BOOLEAN; 
begin 
  // Check if Mixer is available 
  // Uberprufen, ob ein Mixer vorhanden ist 
  nMixerDevs := mixerGetNumDevs(); 
  if (nMixerDevs < 1) then 
  begin 
    Exit; 
  end; 
 
  // open the mixer 
  intRet := mixerOpen(@hMix, 0, 0, 0, 0); 
  if intRet = MMSYSERR_NOERROR then 
  begin 
    mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE; 
    mxl.cbStruct        := SizeOf(mxl); 
 
    // mixerline info 
    intRet := mixerGetLineInfo(hMix, @mxl, MIXER_GETLINEINFOF_COMPONENTTYPE); 
 
    if intRet = MMSYSERR_NOERROR then 
    begin 
      ZeroMemory(@mxlc, SizeOf(mxlc)); 
      mxlc.cbStruct := SizeOf(mxlc); 
      mxlc.dwLineID := mxl.dwLineID; 
      mxlc.dwControlType := MIXERCONTROL_CONTROLTYPE_MUTE; 
      mxlc.cControls := 1; 
      mxlc.cbmxctrl := SizeOf(mxc); 
      mxlc.pamxctrl := @mxc; 
 
      // Get the mute control 
      intRet := mixerGetLineControls(hMix, @mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE); 
 
      if intRet = MMSYSERR_NOERROR then 
      begin 
        ZeroMemory(@mxcd, SizeOf(mxcd)); 
        mxcd.cbStruct := SizeOf(TMIXERCONTROLDETAILS); 
        mxcd.dwControlID := mxc.dwControlID; 
        mxcd.cChannels := 1; 
        mxcd.cbDetails := SizeOf(MIXERCONTROLDETAILS_BOOLEAN); 
        mxcd.paDetails := @mcdMute; 
 
        mcdMute.fValue := Ord(bMute); 
 
        // set, unset mute 
        intRet := mixerSetControlDetails(hMix, @mxcd, 
          MIXER_SETCONTROLDETAILSF_VALUE); 
          { 
          mixerGetControlDetails(hMix, @mxcd, 
                                 MIXER_GETCONTROLDETAILSF_VALUE); 
          Result := Boolean(mcdMute.fValue); 
          } 
        Result := intRet = MMSYSERR_NOERROR; 
 
        if intRet <> MMSYSERR_NOERROR then 
          ShowMessage('SetControlDetails Error'); 
      end 
      else 
        ShowMessage('GetLineInfo Error'); 
    end; 
 
    intRet := mixerClose(hMix); 
  end; 
end; 
 
procedure TForm1.Button1Click(Sender: TObject); 
begin 
  SetMicrophoneVolumeMute(False); 
end; 

{********************************************************} 
 
// Enable/disable "Mute" for several mixer line sources. 
 
uses 
  MMSystem; 
 
type 
 TMixerLineSourceType = (lsDigital, lsLine, lsMicrophone, lsCompactDisk, lsTelephone, 
                         lsWaveOut, lsAuxiliary, lsAnalog, lsLast); 
 
function SetMixerLineSourceMute(AMixerLineSourceType: TMixerLineSourceType; bMute: Boolean): Boolean; 
var 
  hMix: HMIXER; 
  mxlc: MIXERLINECONTROLS; 
  mxcd: TMIXERCONTROLDETAILS; 
  vol: TMIXERCONTROLDETAILS_UNSIGNED; 
  mxc: MIXERCONTROL; 
  mxl: TMixerLine; 
  intRet: Integer; 
  nMixerDevs: Integer; 
  mcdMute: MIXERCONTROLDETAILS_BOOLEAN; 
begin 
  Result := False; 
  // Check if Mixer is available 
  nMixerDevs := mixerGetNumDevs(); 
  if (nMixerDevs < 1) then 
  begin 
    Exit; 
  end; 
 
  // open the mixer 
  intRet := mixerOpen(@hMix, 0, 0, 0, 0); 
  if intRet = MMSYSERR_NOERROR then 
  begin 
    ZeroMemory(@mxl, SizeOf(mxl)); 
    case AMixerLineSourceType of 
      lsDigital: mxl.dwComponentType :=MIXERLINE_COMPONENTTYPE_SRC_DIGITAL; 
      lsLine: mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_LINE; 
      lsMicrophone: mxl.dwComponentType :=MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE; 
      lsCompactDisk: mxl.dwComponentType :=MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC; 
      lsTelephone: mxl.dwComponentType :=MIXERLINE_COMPONENTTYPE_SRC_TELEPHONE; 
      lsWaveOut: mxl.dwComponentType :=MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT; 
      lsAuxiliary: mxl.dwComponentType :=MIXERLINE_COMPONENTTYPE_SRC_AUXILIARY; 
      lsAnalog : mxl.dwComponentType :=MIXERLINE_COMPONENTTYPE_SRC_ANALOG; 
      lsLast: mxl.dwComponentType :=MIXERLINE_COMPONENTTYPE_SRC_LAST; 
    end; 
 
    // mixerline info 
    mxl.cbStruct := SizeOf(mxl); 
    intRet := mixerGetLineInfo(hMix, @mxl, MIXER_GETLINEINFOF_COMPONENTTYPE); 
 
    if intRet = MMSYSERR_NOERROR then 
    begin 
      ZeroMemory(@mxlc, SizeOf(mxlc)); 
      mxlc.cbStruct := SizeOf(mxlc); 
      mxlc.dwLineID := mxl.dwLineID; 
      mxlc.dwControlType := MIXERCONTROL_CONTROLTYPE_MUTE; 
      mxlc.cControls := 1; 
      mxlc.cbmxctrl := SizeOf(mxc); 
      mxlc.pamxctrl := @mxc; 
 
      // Get the mute control 
      intRet := mixerGetLineControls(hMix, @mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE); 
 
      if intRet = MMSYSERR_NOERROR then 
      begin 
        ZeroMemory(@mxcd, SizeOf(mxcd)); 
        mxcd.cbStruct := SizeOf(TMIXERCONTROLDETAILS); 
        mxcd.dwControlID := mxc.dwControlID; 
        mxcd.cChannels := 1; 
        mxcd.cbDetails := SizeOf(MIXERCONTROLDETAILS_BOOLEAN); 
        mxcd.paDetails := @mcdMute; 
 
        mcdMute.fValue := Ord(bMute); 
 
        // set, unset mute 
        intRet := mixerSetControlDetails(hMix, @mxcd, MIXER_SETCONTROLDETAILSF_VALUE); 
        { 
        mixerGetControlDetails(hMix, @mxcd, IXER_GETCONTROLDETAILSF_VALUE); 
        Result := Boolean(mcdMute.fValue); 
        } 
        Result := intRet = MMSYSERR_NOERROR; 
 
        if intRet <> MMSYSERR_NOERROR then 
          ShowMessage('SetControlDetails Error'); 
      end 
      else 
        ShowMessage('GetLineInfo Error'); 
    end; 
    intRet := mixerClose(hMix); 
  end; 
end; 
 
// Example Call; 
 
procedure TForm1.Button1Click(Sender: TObject); 
begin 
  SetMixerLineSourceMute(lsLine, True); 
end; 

Взято с сайта https://www.swissdelphicenter.ch/en/tipsindex.php