QAudioInput problem

I'm trying to get voice from my speaker.Can you help me

aaa::aaa(QObject *parent) : QObject(parent)
{
socket = new QUdpSocket;
socket->bind(5000);
connect(socket, &QUdpSocket::readyRead, this, &aaa::processData);

}

void aaa::formatls()
{
QAudioFormat format;
format.setSampleRate(8000);
format.setChannelCount(1);
format.setSampleSize(8);
format.setCodec("audio/pcm");
format.setByteOrder(QAudioFormat::LittleEndian);
format.setSampleType(QAudioFormat::UnSignedInt);

QAudioDeviceInfo info = QAudioDeviceInfo::defaultInputDevice();
if (!info.isFormatSupported(format))
format = info.nearestFormat(format);

audio = new QAudioInput(format, this);
connect(audio, SIGNAL(stateChanged(QAudio::State)), this, SLOT(handleStateChanged(QAudio::State)));

audio->start(); // Im not sure about this part where should I write audio->start()? I just try to combine codes that i saw

}

void Network::processData()
{
QByteArray Datays;
Datays = socket->readAll();

}