说明：代码部分是基于古月居前辈的例程，在此对胡老师表示感谢！！

语音交互功能框图:

/* main thread: start/stop record ; query the result of recgonization.
 * record thread: record callback(data write)
 * helper thread: ui(keystroke detection)
 */
int main(int argc, char* argv[])
{
    // 初始化ROS
    ros::init(argc, argv, "voiceRecognition");
    ros::NodeHandle n;
    ros::Rate loop_rate(10);

    // 声明Publisher和Subscriber
    // 订阅唤醒语音识别的信号
    ros::Subscriber wakeUpSub = n.subscribe("voiceWakeup", 1000, WakeUp);   
    // 订阅唤醒语音识别的信号    
    ros::Publisher voiceWordsPub = n.advertise<std_msgs::String>("voiceWords", 1000);  

    ROS_INFO("Sleeping...");
    int count=0;

    int ret = MSP_SUCCESS;
    /* login params, please do keep the appid correct */
    const char* login_params = "appid = 594a7b46, work_dir = .";
    int aud_src = 0; /* from mic or file */

    /*
    * See "iFlytek MSC Reference Manual"
    */
    const char* session_begin_params =
        "sub = iat, domain = iat, language = zh_cn, "
        "accent = mandarin, sample_rate = 16000, "
        "result_type = plain, result_encoding = utf8";

    /* Login first. the 1st arg is username, the 2nd arg is password
     * just set them as NULL. the 3rd arg is login paramertes 
     * */
    ret = MSPLogin(NULL, NULL, login_params);
    if (MSP_SUCCESS != ret)	{
        printf("MSPLogin failed , Error code %d.\n",ret);
        goto exit; // login fail, exit the program
    }

    while(ros::ok())
    {
        // 语音识别唤醒     
        if(wakeupFlag)
        {
            ROS_INFO("Wakeup...");

	        printf("Demo recognizing the speech from microphone\n");
	        printf("Speak in 8 seconds\n");

	        demo_mic(session_begin_params);

	        printf("8 sec passed\n");
            
            wakeupFlag=0;
        }

        // 语音识别完成
        if(resultFlag){
            resultFlag=0;
            std_msgs::String msg;
            msg.data = g_result;
            voiceWordsPub.publish(msg);
        }

        ros::spinOnce();
        loop_rate.sleep();
        count++;
    }
exit:
	MSPLogout(); // Logout...

	return 0;
}

WakeUp()函数:

void WakeUp(const std_msgs::String::ConstPtr& msg)
{
    printf("waking up\r\n");
    usleep(700*1000);
    wakeupFlag=1;
}

demo_mic()函数:

/* demo recognize the audio from microphone */
static void demo_mic(const char* session_begin_params)
{
	int errcode;
	int i = 0;

	struct speech_rec iat;

	struct speech_rec_notifier recnotifier = {
		on_result,
		on_speech_begin,
		on_speech_end
	};

	errcode = sr_init(&iat, session_begin_params, SR_MIC, &recnotifier);
	if (errcode) {
		printf("speech recognizer init failed\n");
		return;
	}
	errcode = sr_start_listening(&iat);
	if (errcode) {
		printf("start listen failed %d\n", errcode);
	}
	/* demo 8 seconds recording */
	while(i++ < 8)
		sleep(1);
	errcode = sr_stop_listening(&iat);
	if (errcode) {
		printf("stop listening failed %d\n", errcode);
	}

	sr_uninit(&iat);
}

demo_file()函数：

/* demo send audio data from a file */
static void demo_file(const char* audio_file, const char* session_begin_params)
{
	int	errcode = 0;
	FILE*	f_pcm = NULL;
	char*	p_pcm = NULL;
	unsigned long	pcm_count = 0;
	unsigned long	pcm_size = 0;
	unsigned long	read_size = 0;
	struct speech_rec iat;
	struct speech_rec_notifier recnotifier = {
		on_result,
		on_speech_begin,
		on_speech_end
	};

	if (NULL == audio_file)
		goto iat_exit;

	f_pcm = fopen(audio_file, "rb");
	if (NULL == f_pcm)
	{
		printf("\nopen [%s] failed! \n", audio_file);
		goto iat_exit;
	}

	fseek(f_pcm, 0, SEEK_END);
	pcm_size = ftell(f_pcm);
	fseek(f_pcm, 0, SEEK_SET);

	p_pcm = (char *)malloc(pcm_size);
	if (NULL == p_pcm)
	{
		printf("\nout of memory! \n");
		goto iat_exit;
	}

	read_size = fread((void *)p_pcm, 1, pcm_size, f_pcm);
	if (read_size != pcm_size)
	{
		printf("\nread [%s] error!\n", audio_file);
		goto iat_exit;
	}

	errcode = sr_init(&iat, session_begin_params, SR_USER, &recnotifier);
	if (errcode) {
		printf("speech recognizer init failed : %d\n", errcode);
		goto iat_exit;
	}

	errcode = sr_start_listening(&iat);
	if (errcode) {
		printf("\nsr_start_listening failed! error code:%d\n", errcode);
		goto iat_exit;
	}

	while (1)
	{
		unsigned int len = 10 * FRAME_LEN; /* 200ms audio */
		int ret = 0;

		if (pcm_size < 2 * len)
			len = pcm_size;
		if (len <= 0)
			break;

		ret = sr_write_audio_data(&iat, &p_pcm[pcm_count], len);

		if (0 != ret)
		{
			printf("\nwrite audio data failed! error code:%d\n", ret);
			goto iat_exit;
		}

		pcm_count += (long)len;
		pcm_size -= (long)len;		
	}

	errcode = sr_stop_listening(&iat);
	if (errcode) {
		printf("\nsr_stop_listening failed! error code:%d \n", errcode);
		goto iat_exit;
	}

iat_exit:
	if (NULL != f_pcm)
	{
		fclose(f_pcm);
		f_pcm = NULL;
	}
	if (NULL != p_pcm)
	{
		free(p_pcm);
		p_pcm = NULL;
	}

	sr_stop_listening(&iat);
	sr_uninit(&iat);
}