Hearing Krishna katha leads to trance

When we first hear, we gradually start to accept the message. As we hear more, we not only accept but start liking the message. In other words, we become attached to the message. If we continue our hearing, our attachment will lead to chanting/recitation and eventually to remembering.

This remembrance,however, is periodical at this point. So we continue our hearing. As we hear more, our remembrance leads to recollection of the memory. As we recollect more, we become more absorbed in memory of our recollection. This absorption further intensifies our remembering. As our absorption increases, that remembrance which was periodical starts to become frequent and constant. As constant remembrance (meditation) increases, one enters into spiritual samadhi or trance (constant meditation). (paraphrased from Nectar of Instruction, Text 8 purport)

Basically it goes like this in that order

1. Hearing
2. Acceptance
3. Attachment
4. Chanting or Recitation
5. Remembrance
6. Recollection
7. Absorption
8. Meditation (constant remembrance)
9. Spiritual trance (constant meditation)

Hare Krishna