Final answer:
The evidence that information in the unattended ear is not processed deeply comes from dichotic listening tasks and the auditory system's selectivity for certain frequencies that are important for understanding conversation or appreciating music. Bone conduction tests distinguish the type of hearing damage, further illustrating the complexity of auditory processing.
Step-by-step explanation:
The evidence that the unattended ear is not processed deeply lies in auditory selective attention research. Studies show that information presented to the unattended ear during a dichotic listening task is not consciously perceived and is poorly remembered, indicating superficial processing. In such tasks, subjects focus on one ear's input (the attended ear) and often cannot recall specific details provided to the other ear.
Functional aspects of the auditory system further support this, given the ear's selective sensitivity to certain frequencies. For example, the ear is not particularly sensitive to frequencies around 11.0 kHz, meaning we don't hear overtones that are due to the ear canal characteristics. Additionally, hearing loss conditions, like presbycusis, underscore the limits of auditory processing. For instance, presbycusis represents a progressive loss of higher frequency hearing with age, which impacts the ability to process sounds thoroughly.
Bone conduction tests can also distinguish between nerve damage and middle ear damage, showing the different pathways and processing levels in the hearing system. If parts like the malleus or incus are missing, the transmission of sound to the cochlea is impeded, leading to hearing problems, which suggests importance in the depth of sound processing within the ear.