Генерация звука через сист. динамик Visual С++

#include <windows.h>

typedef struct _BEEP_SET_PARAMETERS {
    ULONG Frequency;
    ULONG Duration;
} BEEP_SET_PARAMETERS, *PBEEP_SET_PARAMETERS;

#define IOCTL_BEEP_SET \
    CTL_CODE(FILE_DEVICE_BEEP, 0, METHOD_BUFFERED, FILE_ANY_ACCESS)

//System dynamic wrapper
struct Beeper
{
    //only single instance allowed
    static Beeper& getInstance()
    {
        static Beeper instance;
        return instance;
    }

    void sound()
    {
        if(isGood() && beepParameters.Frequency != 0)
        {
             DWORD dwReturned;
            DeviceIoControl(hBeep, IOCTL_BEEP_SET, &beepParameters,
                sizeof(BEEP_SET_PARAMETERS),
                NULL, 0, &dwReturned, NULL);
        }
    }

    void noSound()
    {
        if(isGood())
        {
            DWORD dwReturned;

            beepParameters.Frequency = 0;

            DeviceIoControl(hBeep, IOCTL_BEEP_SET, &beepParameters,
                sizeof(BEEP_SET_PARAMETERS),
                NULL, 0, &dwReturned, NULL);
        }
    }

    inline void setFrequency(UINT frequency)
    {
        beepParameters.Frequency = frequency;
    }

    inline bool isGood() const
    {
        return hBeep != INVALID_HANDLE_VALUE;
    }

//only single instance allowed    
private:
   
    Beeper() : hBeep(INVALID_HANDLE_VALUE)
    {
        DefineDosDevice(DDD_RAW_TARGET_PATH, deviceName,
            _T("\\Device\\Beep"));

        hBeep = CreateFile(fileName,
            FILE_GENERIC_READ | FILE_GENERIC_WRITE,
            0, NULL, OPEN_EXISTING, 0, NULL);

        beepParameters.Duration = 0xFFFFFFFF;
        beepParameters.Frequency = 0;
    }

    ~Beeper()
    {
        if(isGood())
            CloseHandle(hBeep);

        DefineDosDevice(DDD_REMOVE_DEFINITION, deviceName, NULL);
    }

    Beeper& operator=(const Beeper&);
    Beeper(const Beeper&);

private:
    static const TCHAR fileName[];
    static const TCHAR *deviceName;
    HANDLE hBeep;
    BEEP_SET_PARAMETERS beepParameters;
};
const TCHAR Beeper::fileName[] =
        _T("\\\\.\\{1127385F-E5BA-4dc6-A0A2-48ECD2F1AB9A}");

const TCHAR *Beeper::deviceName =
        fileName + (sizeof(_T("\\\\.\\"))  - sizeof(TCHAR)) / sizeof(TCHAR);

Beeper& beeper = Beeper::getInstance();