Most people can handle at least 4 audios meant to create permanent physical changes.
You can listen to as many audios as you like so long as your physical and energy body can handle the fields.
Experimentation is one of the best ways to discover what works for you as each person has unique individual experiences. The number of different fields that you can use generally increases over time as well.
You can listen to as many audios as you like which create energetic changes such as The Chi Elixir, or temporary boosts such as Glutathione Super Anti-Oxidant.
Here is a thread with a more detailed answer to a similar question: