Audio files on this site are in mp3 format. They can be played by free software. On most computers, such a programme will start automatically when you click on the link to an audio file. If this does not happen, please download a free player such as RealPlayer, Winamp or Windows Media Player.
Audio files on this site can also be downloaded onto hard drives for later listening, or to portable players such as iPods.
Some links from this site are to PDF files. The PDF file format is widely used for printed documents such as journal articles. It retains the format of the original, and is easy to print.
PDF files are read by free software such as Adobe Reader. Most computers will automatically start Adobe Reader when you click on the link for a PDF file. If this does not happen, it probably means that you need to download Adobe Reader from Adobe.com.