Cannot get any sound

On playback after attempting to record there is no sound. I am not getting the waves while sound is playing only some lines working themselves through,any ideas please

What is set as the playback device in the device toolbar?
If you restart Audacity, then generate a “Tone” (using the Tone generator in the “Generate” menu with default settings) and then press the Play button, do you hear the tone play (a 30 second “beep”)?