I'm going to disagree with the other two answers.
I do not think it's even remotely humane. Your dog has the reasoning capability of a toddler, and for all the reasons you wouldn't put a shock collar on a toddler, you shouldn't put one on a dog.
Your dog trusts you and thinks of you as part of it's family. If you hurt your dog, you betray that trust. It's not about the pain level, as much as the systematic abuse of your dog's trust.
More fundamentally though - negative reinforcement is very unreliable, for the very simple reason that you cannot control what you're dog is associating that negative reinforcement with. That doesn't matter if it's a shock collar or taking a stick to it.
If a dog is barking or whining, they're not doing so just randomly, any more than a baby cries just to piss you off. It's doing so in response to something. If you punish a dog for reacting to something, then it's just as likely to associate the punishment with the thing they're reacting to. Or you. Or some environmental factor. You've simply no control over what they think they've been punished for.
Or worse yet - they may not realise at all, they'll perceive it as just random pain, and start to become very anxious and stressed (and maybe do the think you don't like even more as a result).
Consider if you will - a dog barks at the postman. You electrocute your dog to make it stop. Have you just taught it not to bark, or have you convinced it that it was right all along, and the postman is a threat? You can end up in a very rapid spiral of defensiveness and aggression very easily, to the point where you'll do such a lot of psychological damage to your dog that it can no longer be trusted, because it'll have learned with some very strong stimulus that there's a threat they don't properly understand.
So no, I don't think this is a good idea - it may work short term, but it's a massive betrayal of trust and will significantly and permanently damage your dog's mental health.
If your dog is doing something you want it to stop, the most effective approach is gentle positive reinforcement of incompatible behaviours. If your dog is prone to chasing, teach it to sit. It can't do both, and so it'll do the thing that is 'most positive'. You can train a dog into 'quiet' - it's not easy, because it's not doing something - first you need to train 'make a noise' (often 'speak') because then you can predict the stopping - and cuing/reinforcing.
The humane society has some suggestions for this sort of thing: http://www.humanesociety.org/animals/dogs/tips/how_to_stop_barking.html
References:
"I came to the conclusion that dogs had the mental ability roughly equivalent to a human two-year-old. Further work led me to believe that the most intelligent dogs might have the mental abilities similar to a human two-and-a-half-year-old child"
Anyone who applies aversives when training a dog should have a very clear understanding of what they are doing and how/why it works. Aversives applied without knowledge and skill lead to all kinds of problems, from poor training outcomes to aggressive behaviors.
We are against the use of any negative training method
or device and believe that their use is both irresponsible
and ineffective.
"As a dog will have no idea what has caused the pain, it is far more likely to associate it with something in its immediate environment than to connect it with its own behaviour at the time."
Whilst a bit 'sciencey' concludes - Overall conclusions P31:
The combination of differences in individual dog‟s perception of stimuli, different stimulus strength and
characteristics from collars of different brands, differences between momentary and continuous stimuli,
differences between training advice in manuals, differences in owner understanding of training approaches and
how owners use the devices in a range of different circumstances are likely to lead to a wide range of training
experiences for pet dogs.
-
There was no difference in owner reported perceived success or ease of training between e-collars and other
training methods
-
These findings suggest that the experience of a stimulus is sufficiently
aversive in at least a proportion of dogs for them to experience negative emotions when trained in the situation
which may predict collar use.
So - no more effective, and distressing to your dog.
I would also recommend reading:
"In Defence of Dogs" - this also contains citations, however I have quoted directly:
It seems very likely that these dogs were associating the shocks with their handlers, as well as with the mistakes the dogs had made that triggered the shocks. When the shock is not timed properly, the dog’s fear and anxiety may become even worse than this.
Ref: Matthijs Schilder and Joanne van der Borg, ‘Training dogs with help of the shock collar: short and long term behavioural effects’, Applied Animal Behaviour Science, 85 (2004), pp. 319– 34.
Bradshaw, John (2011-07-11). In Defence of Dogs: Why Dogs Need Our Understanding (Kindle Locations 5060-5062). Penguin Books Ltd. Kindle Edition.
a growing body of evidence indicates that in inexpert hands physical punishment is not only likely to harm the dog but is ineffective as well. Two separate surveys of dog owners have revealed that dogs trained with punishment tend to be less obedient and more fearful than those trained with reward.
(Ref: Elly Hiby, Nicola Rooney and John Bradshaw, ‘Dog training methods: their use, effectiveness and interaction with behaviour and welfare’, Animal Welfare, 13 (2004), pp. 63– 9.)
Bradshaw, John (2011-07-11). In Defence of Dogs: Why Dogs Need Our Understanding (Kindle Locations 2090-2092). Penguin Books Ltd. Kindle Edition.
And perhaps slightly frivolously, but because I think it's rather fun (and a little more light hearted reading than the rest of the above:
"What Shamu taught me about a happy marriage" - on 'least reinforcing stimulus'.