Conductive hearing loss occurs when sound is not conducted through the external auditory canal to the tympanic membrane and the ossicles. Causes include acute otitis media, performated eardrum, impacted cerumen (earwax), or a foreign body in the external canal. A sensorineural hearing loss occurs when there is damage to the fine hairs in the cochlea caused by loud noise.

The "malleus," "incus," and "stapes" are the three bones that make up the ossicles of the middle ear. Together they work to transform sound waves into mechanical vibrations. The "pinna" is not a bone at all, but rather the anatomical term for the fleshy, cartilaginous outer ear.

The ossicle that attaches directly to the tympanic membrane is the malleus, or "hammer." This bone articulates with the incus, or "anvil," which then articulates with the stapes, or "stirrup" (so called because of it's resemblance to the stirrup of a saddle). The stapes in turn attaches to the oval window of the fluid-filled inner ear. 

The main sensory organ of hearing is a small structure within the cochlea called the “organ of Corti.” It contains hair cells, which are sensory receptor cells capable of responding to changes in pressure of the fluid of the inner ear. The organ of Corti is sandwiched between the three fluid-filled chambers, or scalae: the scala vestibuli, the scala tympani, and the scala media.

The “bony labyrinth” is a separate part of the inner ear that plays a role in balance and equilibrium. The “eustachian tube” is not a part of the inner ear, but rather a channel between the middle ear and the pharynx.

The eustachian tube primarily functions to equalize pressure between the middle ear and the atmosphere, remove cellular and bacterial waste from the middle ear, and to drain fluid from the middle ear into the pharynx. Cells within the inner ear produce perilymph. 

The “cocktail party effect” accounts for the fact that we are able to hear personally important information even if we are not involved with it. In this example, George was in a conversation amongst his friends, and not involved with the conversation of the group nearby. The cocktail party effect explains that even though he was not directly paying attention to the nearby conversation, he did not completely filter the information out. Instead, it is was if he "turned the volume down" and paid attention once the information became personally relevant, such as the mentioning of his brother's name.

“Divided attention” is when an individual focuses on multiple tasks at once. While it could be argued that George is attending to two conversations at once, the cocktail party effect best describes the reason he is able to hear his brother's name without any attempt to listen to two conversations at once. The “primacy effect” concerns our tendency to have better memory for things at the beginning of a list (e.g. if you are given a list of words to remember, you will be more likely to remember the ones at the beginning rather than ones in the middle of the list). “Heuristics” are short cuts used for problem solving. Last, “schemas” are mental frameworks we use for understanding new experiences.

A confounding variable is an extraneous variable that is inadvertently associated with the independent or dependent variables. The just-noticeable difference of a stimulus can change substantially over the course of a person's lifespan. In this case, age is associated with differences in hearing abilities. Normative hearing loss and certain medical conditions that contribute to hearing loss are more common as age increases. The other options (marital status, IQ, and depressive symptoms) are not associated with changes in hearing. 

The primary auditory cortex, the area of the brain responsible for processing auditory information, is located bilaterally in the temporal lobes in Brodmann areas 41 and 42.