We get a variety of source material in the IELTS listening. The first two sections present recordings related to social needs and last two sections deal with education and training. The reason that we get these types of materials is that the IELTS listening test is same for both academic module and general training module.
Furthermore, the tapes are also different when it comes to the number of people involved in it. Some tapes involve only one person and some other involver many. To be precise we can say that section 1&3 of the IELTS listening test present conversations whereas section 2&4 present monologues.
The listening question booklet accompanying the IELTS listening module also exhibit this heterogeneity. The test-taker is provided with normal sentences, notes and tables. The test-taker will also get maps, plans, and diagrams.
The accents and pronunciations provided in the IELTS listening also vary considerably. We get a variety of accents prevailing in all major English-speaking countries including the UK, Canada, Australia, New Zealand, and the US,though Australian and British accents are so common. Sometimes accents that are heavily influenced by languages other than English will also be presented for example. English influenced by Indian or Japanese languages.