Is it permissible to listen to some shaykhs without my husband's knowledge?

It is permissible for a woman to listen to men as long as she does not fear temptation. It is also permissible for her to go out to seek obligatory knowledge, such as [learning about] religious duties and menstruation rulings, without her husband's permission. However, it is preferable for her to listen to him [the teacher/lecturer] in her home. As for non-obligatory knowledge, she is not required to seek her husband's permission to listen to it, but she must stop listening and attend to his needs if he requires her. No one has made it obligatory for a woman to seek her husband's permission for everything; rather, they have made it obligatory in matters that cause restriction to the husband in his permissible rights, such as voluntary fasting, i'tikaf (seclusion in a mosque), voluntary Hajj, and leaving the house.