I would say that it depends on various factors. There are fields that you can listen as many as you as you like and for those like The Height Booster (Grow Taller Version 2.0, energetic audio) count toward the limit. This limit can change if you get faster results anyway.
I think that the idea is not to get your energy system overwhelmed, tired or depleted of energy, thus possibly slowing results. You could always try to manifest in your reality about the energy and states to listen to more fields.
You can look at the links to the posts below for more info.
Limit or recommendations for the number of fields
@SammyG Listening guidelines, post #10
Jing Restoration and Pranayama
@Philip_Weiss (en passant, je parle français aussi, salut haha) mentioned them on topic A weird problem, post #2 and Listening Guidelines, post #99. User @uial replied with the same conclusion.
https://forum.enlightenedstates.com/t/a-weird-problem/952/2?u=strongemery
https://forum.enlightenedstates.com/t/listening-guidelines/22/99?u=strongemery
@gpo mentioned on Listening guidelines, post #131 the Energy Expansion card to handle more fields as well as the Attunement card and the Field Booster. There is the Attunement card to do first if you have never tried this before.