Hi！guys, How can I get the data after sound change with the type of byte[]

FMOD Engine
3

Well,There is my code(Java Language):
====== code start ======
private byte[] doVoice(){
AudioFrame frame = getAudioFrame();
ByteBuffer byteBuffer = frame.getData();
byte[] inputBuffer = new byte[byteBuffer.limit()];
byte[] outputBuffer = new byte[byteBuffer.limit()];
byteBuffer.get(inputBuffer);
outputBuffer = VoiceTools.changeVoice(1, inputBuffer);
return outputBuffer;
}
====== code end ======
so,the data format of voice is byte[],and how could I to deal these data with FMOD?