How to save music effect

We have a feature, to save changed voice effect. But now I can play sound effect,can not save it.
Could you give me a help ?

now I try it below,it can not success. I also can not add dsp effect to it. because I do not know how to add it . thanks for help .

    //start  save file----------------------------------

    const char *path_cstr = env->GetStringUTFChars(path_jstr, NULL);
    system->createSound(path_cstr, FMOD_DEFAULT | FMOD_OPENONLY, NULL, &sound);
    Retrieve the sound information for the Impulse Response input file
    FMOD_RESULT result;
    FMOD_SOUND_FORMAT irSoundFormat;
    FMOD_SOUND_TYPE irSoundType;
    int irSoundBits, irSoundChannels;
    result = sound->getFormat(&irSoundType, &irSoundFormat, &irSoundChannels, &irSoundBits);
    unsigned int irSoundLength;
    result = sound->getLength(&irSoundLength, FMOD_TIMEUNIT_PCM);

    if (irSoundFormat != FMOD_SOUND_FORMAT_PCM16)
            For simplicity of the example, if the impulse response is the wrong format just display an error
        LOGI("%s", "not pcm");

        The reverb unit expects a block of data containing a single 16 bit int containing
        the number of channels in the impulse response, followed by PCM 16 data
    unsigned int irDataLength = sizeof(short) * (irSoundLength * irSoundChannels + 1);
    short* irData = (short*)malloc(irDataLength);
    irData[0] = (short)irSoundChannels;
    unsigned int irDataRead;
    result = sound->readData(&irData[1], irDataLength - sizeof(short), &irDataRead);
    FILE *fpw = fopen("sdcard/voice_changed.pcm","wb+");
    fwrite(&irData[1], irDataLength, sizeof(short), fpw);
    //end save file----------------------------------

It looks like you are using our convolution reverb example as a guide, it also shows you how to make and add a DSP to channel or channelgroup.

Are you getting any errors or warnings?