There are several podcasts and audio resources available that discuss geography optional topics for UPSC preparation. These resources provide valuable insights, in-depth analysis, and comprehensive coverage of various geography concepts, theories, and case studies. Here are a few recommended podcasts and audio resources:

1. The UPSC Geography Optional Podcast
This podcast is specifically designed for UPSC aspirants who have chosen geography as their optional subject. It covers a wide range of topics such as physical geography, human geography, environmental geography, and regional geography. The podcast episodes are structured in a way that simplifies complex concepts and provides a comprehensive understanding of the subject.

2. The Geography and World Cultures Podcast
This podcast explores various geographical concepts and their impact on world cultures. It delves into the connections between geography, history, and culture, highlighting the interplay between physical geography and human activities. The episodes cover topics like population geography, urbanization, climate change, and geopolitical issues.

3. The Worldly Marketer Podcast
While not specifically focused on geography optional topics, this podcast provides valuable insights into global marketing and business practices. It explores the geographical aspects of international trade, globalization, and cultural influences on consumer behavior. Understanding these concepts can be beneficial for answering questions related to economic geography and global trade in the UPSC exam.

4. The BBC Radio 4's 'In Our Time' Podcast
This podcast covers a wide range of topics, including geography-related subjects. It features discussions and debates with experts from various fields. While not exclusively focused on geography optional topics, it provides a broader perspective on historical, cultural, and scientific aspects that can be relevant for UPSC preparation.

5. EduRev's Geography Optional Audio Notes
EduRev offers comprehensive audio notes specifically designed for geography optional subjects. These audio resources cover various topics in detail, including physical geography, human geography, and regional geography. The content is structured in a way that provides a comprehensive understanding of concepts, making it an excellent resource for UPSC aspirants.

By utilizing these podcasts and audio resources, UPSC aspirants can gain a deeper understanding of geography optional topics, enhance their knowledge base, and improve their exam preparation. It is recommended to supplement these resources with textbooks, study materials, and regular revision to consolidate the learning.