Skin is the soft outer tissue covering vertebrates. Other animal coverings, such as the arthropod exoskeleton have different developmental origin, structure and chemical composition. The adjective cutaneous means of the skin (from Latin cutis, skin).
Sorry to hear about your problem. The numbness in the ear can be due to variety of reasons. Some of them are. Diabetes. Peripheral neuropathy. Sensory nerve trauma. Ear infection. Cold. Cerebro vascular accident. Ear injury etc. As there is no history of trauma, so ear injury and sensory nerve trauma can be ruled out. Diabetes can be detected by undergoing a blood glucose test. This numbness can be caused by a preceding throat infection which can result in ear infection leading to numbness.
The echo that you are describing could most likely be due to an Eustachian tube dysfunction which is generally seen when you are suffering from cold. The Eustachian tube connects the middle of the ear to the back of the throat and maintains the pressure in the inner ear. When there is an infection or cold, this gets blocked leading to the symptoms.This echo sensation will go off on its own and no treatment is usually required.