A few days ago, Conycatcher wrote:
Being able to understand everything in a TV program is quite an accomplishment…. May I ask if as part of reaching this stage you spent a long time watching TV for several hours a day? If so about how long? …it’s hard to find time to spend lots of time watching TV, although I’m sure I’m at the stage where it would be very helpful. Sometimes when I watch TV I can understand about 80% of what they say without looking at the characters, but sometimes I can barely understand anything.
(Edited slightly for brevity.)
Indeed, for shows which have relatively simple Cantonese, such as 愛回家 and most anime, I can understand around 97% of what they’re saying the first time around. The remainder can be picked up from a second viewing, either from subtitles or by listening carefully. For harder shows, such as historical dramas or police-themed ones, my comprehension drops to about 80% – I almost always know exactly what’s going on, but a percentage of 成語 or slangy phrases will often evade my grasp for a while.
As for how much time I spent watching: this year, I spent a couple of weeks watching every episode of 鋼之煉金術師, and another couple of weeks smashing through 地獄少女, to give but a couple of examples. I guess for the periods where I was going through such shows, I was watching for about 4 hours a day on average, which seemed to be the right amount for actually improving listening comprehension.
When one is at the 80%, I think the thing to do is to just to turn the TV on and leave it on, in much the same way that AJATT recommends, although I am convinced that creating your own listening material will also give one’s listening skills a huge boost because of the i+1 format.
 For the total 5 year period of learning Cantonese and Mandarin though, the average is probably more like 2 hours a day, at most. Rarely, there were days of 8 hours, and commonly, there were days of 0 hours. It depended mostly on what TV shows were being shown at what time.