Seth S. Horowitz from the New York Times provides a great explanation, “the difference between the sense of hearing and the skill of listening is attention.
Hearing is a vastly underrated sense. We tend to think of the world as a place that we see, interacting with things and people based on how they look. Studies have shown that conscious thought takes place at about the same rate as visual recognition, requiring a significant fraction of a second per event. But hearing is a quantitatively faster sense. While it might take you a full second to notice something out of the corner of your eye, turn your head toward it, recognize it and respond to it, the same reaction to a new or sudden sound happens at least 10 times as fast.
This is because hearing has evolved as our alarm system — it operates out of line of sight and works even while you are asleep. And because there is no place in the universe that is totally silent, your auditory system has evolved a complex and automatic “volume control,” fine-tuned by development and experience, to keep most sounds off your cognitive radar unless they might be of use as a signal that something dangerous or wonderful is somewhere within the kilometer or so that your ears can detect.
THIS IS WHERE ATTENTION KICKS IN
Attention is not some monolithic brain process. There are different types of attention, and they use different parts of the brain. The sudden loud noise that makes you jump activates the simplest type: the startle. A chain of five neurons from your ears to your spine takes that noise and converts it into a defensive response in a mere tenth of a second — elevating your heart rate, hunching your shoulders and making you cast around to see if whatever you heard is going to pounce and eat you. This simplest form of attention requires almost no brains at all and has been observed in every studied vertebrate.
More complex attention kicks in when you hear your name called from across a room or hear an unexpected birdcall from inside a subway station. This stimulus-directed attention is controlled by pathways through the temporoparietal and inferior frontal cortex regions, mostly in the right hemisphere — areas that process the raw, sensory input, but don’t concern themselves with what you should make of that sound. (Neuroscientists call this a “bottom-up” response.)
But when you actually pay attention to something you’re listening to, whether it is your favorite song or the cat meowing at dinnertime, a separate “top-down” pathway comes into play. Here, the signals are conveyed through a dorsal pathway in your cortex, part of the brain that does more computation, which lets you actively focus on what you’re hearing and tune out sights and sounds that aren’t as immediately important.
In this case, your brain works like a set of noise-suppressing headphones, with the bottom-up pathways acting as a switch to interrupt if something more urgent — say, an airplane engine dropping through your bathroom ceiling — grabs your attention.”
SO WHAT HAPPENS TO ATTENTION WHEN YOU HAVE A HEARING LOSS?
Researchers have determined that one of the biggest impacts of a hearing loss is the loss of “sound features” needed to properly analyze the acoustic environment.
To put it more simply, if you have no indication of a hearing loss then you will have a much easier time sorting out what you what to hear from what they don’t want to hear then if you have a hearing loss.
THE GOOD NEWS FOR HEARING AID USERS?
Current hearing aids can enhance listening in quiet and improve selective attention in fixed and predictable settings. This is important because anything that increases the speed and ease of object formation or object selection will reduce the processing load on a listener and improve the ability to participate in everyday social settings.
In other words if you have a hearing loss you will hear better in a group if you wear hearing aids.