hear is more unconscious while listening is subconscious . What this means is, for example, if an explosion occurs, a tree falls, someone is speaking, you are hearing the sound. Hearing implies that the sound has reached you, but doesn't mean you understood it. What I mean by this is that you can "hear" someone speak, but doesn't mean you heard them or understood them. Listening is an active form of hearing. It means you are attempting to interpert what you hear.
Speak and talk a bit more complex. Speak is more singular, while talk is plural. What I mean by this is if you speak, you are using not expecting a repaonse from another party. For example, speak at a conference, speak another language (MOSTLY to show ability to do so alone). Now talk is more of a group thing, expecting a response from a third party. For example, talk to the doctor, talk in another language (have a conversation with another in a foreign language).
Hope that helps and it didnt confuse you instead.