Another issue which has presented challenges for media measurement is the consumer habit of "simultaneous media consumption". Modern audiences are often consuming multiple media at the same time. For example, a teenager might be plugged into radio via earphones while working on the Internet, where he or she is scanning online newspapers and magazines. Thus the user may be consuming three or more media alternatives at the same time. Media research companies, which historically specialised in a single media such as radio or TV, were poorly equipped to respond to the challenge of simultaneous consumption across multiple platforms. However, media research is slowly devising methods designed to capture simultaneous media consumption habits.