If you cannot listen to sounds, conversations between characters or videos, check that: - You have a sound card and speakers.
You can perform a technical test: https://technical-test.gamelearn.net/ (press play button and check if you can hear a test signal). - The volume for audio reproductions is correct. - The network you are using allows the downloading of multimedia (.mp3 --> audio and .flv --> video) contents. To find out, you will need to ask your IT manager or technical department.