Object Errors When Implementing Synthesizer Voice in process function

Hi:
I have been designing a synth with a voice class, and everything has been going well until I implemented the voice in the process() function.
I tried creating the voice & implementing it in these ways:
a.

class Processor
{
//...
private:
Voice voice;
};

b.

class Processor
{
//...
private:
Voice* voice;

finally:

process()
{
//...
case: kNoteOnEvent:
{
       Voice* voice;
       voice->noteOn(...);
}
//...
}

All of these create errors in the processor.obj such as:
public: virtual void Voice::noteOn(int, double, float, int, in) is already defined in SynthData.obj
This goes on for each implemented function of the synthesizer’s voice class. Is there something I am doing when declaring the voice class in the processor that redefines it? Help will be much appreciated.
Sincerely,
Sine On Synth