public function createPayload()
    {
        $payloadArray = (object)array();
        $payloadArray->Input['Data'] = $this->getQueryText();
        $payloadArray->Input['Type'] = 'text/plain';

        $payloadArray->OutputFormat['Codec'] = $this->getOptions()->getOutputFormatCodec();
        $payloadArray->OutputFormat['SampleRate'] = (int)$this->getOptions()->getOutputSampleRate();
        $payloadArray->Voice['Language'] = $this->getOptions()->getLanguage();
        $payloadArray->Voice['Name'] = $this->getOptions()->getVoice();
        $payloadArray->Parameters['Rate'] = $this->getOptions()->getParametersRate();

        $this->setPayload(json_encode($payloadArray));
        return $this;
    }