[Ajahn Chah] said that listening to Dhamma talks requires a special attitude:
“Keep listening, keep listening. Don’t just believe what you hear and don’t disbelieve. Make yourself neutral. Keep listening. It will bring good results, and there’s no danger in it.
The peril lies in believing too much in what you hear, or in disbelieving. Listen and contemplate. This is what practice is about: being a listener and being one who reflects on things. As you don’t know yet whether the things you like and dislike are true or not, the Buddha said that, for the time being, you should keep listening.
If you don’t, you’ll just follow your own opinions about things, and if you do that, then you will develop wrong view, and your practice won’t advance. The wise person is one who keeps looking, contemplating, continually reflecting.
The true Dhamma is not something that can be communicated with words. You can’t appropriate someone else’s knowledge. If you take someone else’s knowledge, then you have to meditate on it. Listening to someone else and understanding what they say doesn’t mean that your defilements will come to an end. You have to take that understanding and then chew on it and digest it until it’s a sure thing and really your own.”
This reflection by Ajahn Chah as recounted by Ajahn Jayasaro is from the book, Stillness Flowing,
(pdf) pp. 198-199.