uses
  {...}, AndroidApi.JNI.Media;

procedure MakeSound(ADuration: Integer);
var
  Volume: Integer;
  StreamType: Integer;
  ToneType: Integer;
  ToneGenerator: JToneGenerator;
begin
   Volume := TJToneGenerator.JavaClass.MAX_VOLUME; // Громкость
   StreamType := TJAudioManager.JavaClass.STREAM_ALARM;
   ToneType := TJToneGenerator.JavaClass.TONE_DTMF_0; // Тип звука
   ToneGenerator := TJToneGenerator.JavaClass.init(StreamType, Volume);
   ToneGenerator.startTone(ToneType, ADuration);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
   MakeSound(1000);
end;

uses
  {...}, System.Messaging {TMessageManager}, Androidapi.JNI.GraphicsContentViewText;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
  private
    procedure HandleActivityMessage(const Sender: TObject; const M: TMessage);
    function OnActivityResult(RequestCode, ResultCode: Integer; Data: JIntent): Boolean;
  public
    FMessageSubscriptionID: Integer;
  end;

var
  Form1: TForm1;

implementation

{$R *.fmx}

uses
  System.IOUtils, Androidapi.JNI.Os, Androidapi.JNI.App, Androidapi.JNI.Net,
  Androidapi.JNIBridge, Androidapi.Helpers, Androidapi.JNI.JavaTypes,
  Androidapi.JNI.Provider;

const
  RECORD_VIDEO = 9;

procedure TForm1.Button1Click(Sender: TObject);
var
  VideoIntent: JIntent;
  videoUri: Jnet_Uri;
  AFile: JFile;
  FileName: TFileName;
begin
   FMessageSubscriptionID := TMessageManager.DefaultManager.SubscribeToMessage(
      TMessageResultNotification, HandleActivityMessage);
   VideoIntent := TJIntent.JavaClass.init(
      TJMediaStore.JavaClass.ACTION_VIDEO_CAPTURE);
   if VideoIntent.resolveActivity(SharedActivityContext.getPackageManager()) <> nil then
   begin
      // см. /storage/sdcard0/Documents
      FileName := TPath.Combine(TPath.GetSharedDocumentsPath, 'recording.mp4');
      AFile := TJFile.JavaClass.init(StringToJString(FileName));
      videoUri := TJnet_Uri.JavaClass.fromFile(AFile);
      VideoIntent.putExtra(TJMediaStore.JavaClass.EXTRA_OUTPUT,
         TJParcelable.Wrap((videoUri as ILocalObject).GetObjectID));
      SharedActivity.startActivityForResult(VideoIntent, RECORD_VIDEO);
   end;
end;

procedure TForm1.HandleActivityMessage(const Sender: TObject;
  const M: TMessage);
begin
   if M is TMessageResultNotification then
      OnActivityResult(
         TMessageResultNotification(M).RequestCode,
         TMessageResultNotification(M).ResultCode,
         TMessageResultNotification(M).Value);
end;

function TForm1.OnActivityResult(RequestCode, ResultCode: Integer;
  Data: JIntent): Boolean;
begin
   Result := False;

   TMessageManager.DefaultManager.Unsubscribe(
      TMessageResultNotification, FMessageSubscriptionID);
   FMessageSubscriptionID := 0;

   if RequestCode = RECORD_VIDEO then
   begin
      if ResultCode = TJActivity.JavaClass.RESULT_OK then
      begin
         TThread.Queue(nil, procedure
            begin
               Label1.Text := 'recording completed';
               Invalidate;
            end);
      end;
   end;
end;