They don't need to be actively trained, they associate a ringing bell or any other stimulus with receiving food fairly quickly if it's repeated a few times and is consistent enough that they learn to expect it and so physiologically prepare for it.
conditioned stimulus
The noted psychologist who trained a dog to salivate to the sound of a bell is Ivan Pavlov. His experiments on classical conditioning demonstrated how a neutral stimulus, like a bell, could elicit a conditioned response, such as salivation, when paired repeatedly with an unconditioned stimulus (food). This work laid the foundation for behavioral psychology and the understanding of associative learning.
Pavlov
Pavlov used classical conditioning. Initially, every time he rang the bell, he would give the dog food. The dog began associating the sound of the bell with receiving food. He was then able to ring the bell and make the dog salivate (thinking that it was going to be fed).
Ivan Pavlov was a Russian psychologist who is famously known for his conditioning experiment involving a dog and a bell. What he did was train the dog to salivate by ringing a bell. To do so, Pavlov would place food in front of the dog, and ring the bell. Thus, the dog would salivate at the sight of the food and subconsciously at the sound of the bell. Through conditioning, Pavlov was able to repeat the process until the dog became accustomed to hearing the sound of the bell, and ultimately when the dog heard the bell ring, it would begin to salivate as it had learned to associate the sound of the bell with food, and food resulted in its salivation
Spontaneous recovery refers to the re-emergence of a previously extinguished conditioned response after a period of rest without further conditioning. For example, if a dog has been trained to salivate at the sound of a bell but stops responding after the bell is rung multiple times without food, a few days later, ringing the bell again may result in the dog salivating once more, demonstrating that the conditioned response has spontaneously recovered.
A dog rings a bell to go outside when it has been trained to associate ringing the bell with being let outside to go to the bathroom.
He is one the person which thinks about dog first time, so he told that dogs can learn salivate whenever they see food. 'Hard wired. You should know the what kinds of step to teach dogs from Atozpetcare.com/ ***************** Russian physiologist Ivan Pavlov, noticed that dogs could be trained to salvinate whenever a bell was rung. Even if he entered the room without any food, once the bell rang the dogs would salvinate.
The dog rings the bell to go outside all the time because it has been trained to associate ringing the bell with being let outside to relieve itself.
Generalization is a phenomenon in psychology where conditioned subjects respond to stimuli similar to those they were conditioned to respond to. For example, if a dog is trained to salivate at the sight of a circle, the dog will salivate at the sight of an ellipse as well.
There is no tone that causes a dog to salivate; you need to train a particular dog to do that as it is a learned behavior. You might want to read about the apparently not-so-famous experiment by Ivan Pavlov.
no worries, it probably is just because the dog sees food that he or she really wants.