type
  TRIFFHeader = packed record
    ID : array[0..3] of Char;
    Length: DWORD;
    WaveID: array[0..3] of Char;
  end;
  TFormatHeader = packed record
    ID : array[0..3] of Char;
    Length : DWORD;
    FormatTag : WORD;
    Channels : WORD;
    SamplesPerSec : DWORD;
    AvgBytesPerSec: DWORD;
    BlockAlign : WORD;
    BitsPerSample : WORD;
  end;
  TDataHeader = packed record
    ID : array[0..3] of Char;
    Length: DWORD;
  end;
  TWaveHeader = packed record
    RIFF: TRIFFHeader;
    Format: TFormatHeader;
    Data: TDataHeader;
  end;
  TWaveSample = packed record
    Left: Smallint;
    Right: Smallint;
  end;
  TWaveContent = Array of TWaveSample;

procedure SaveWAVEFile(WaveContent: TWaveContent; FileName: String);
var
  WaveHeader: TWaveHeader;
  FStream: TFileStream;
  WaveLength: Integer;
begin
  try
    FStream := TFileStream.Create(FileName, fmCreate);
    WaveLength := length(WaveContent);

    with WaveHeader do begin
      with RIFF do begin
        ID := 'RIFF';
        Length := 4 + WaveLength * 4 + SizeOf(TFormatHeader) + SizeOf(TDataHeader);
        WaveID := 'WAVE';
      end;
      with Format do begin
        ID := 'fmt ';
        Length := SizeOf(TFormatHeader)-8;
        FormatTag := $0001;
        Channels := 2;
        SamplesPerSec := 44100;
        AvgBytesPerSec := 176400;
        BlockAlign := 4;
        BitsPerSample := 16;
      end;
      with Data do begin
        ID := 'data';
        Length := WaveLength * 4;
      end;
    end;

    FStream.Write(WaveHeader, SizeOf(TWaveHeader));
    FStream.Write(WaveContent, 2048{WaveLength * 4});
  finally
    FStream.Free;
  end;
end;