The audiogram associated with sensory presbycusis is thought to show a sharply sloping high-frequency loss extending beyond the speech frequency range, and clinical evaluation reveals a slow, symmetric, and bilateral progression of hearing loss. Diagnosis
Hearing loss is classified as mild, moderate, severe or profound. Pure-tone audiometry for air conduction thresholds at 250, 500, 1000, 2000, 4000, 6000 and 8000 Hz is traditionally used to classify the degree of hearing loss in each ear. Normal hearing thresholds are considered to be 25 dB sensitivity, though it has been proposed that this threshold is too high, and that 15 dB (about half as loud) is more typical. Mild hearing loss is thresholds of 25–45 dB; moderate hearing loss is thresholds of 45–65 dB; severe hearing loss is thresholds of 65–85 dB; and profound hearing loss thresholds are greater than 85 dB. Tinnitus occurring in only one ear should prompt the clinician to initiate further evaluation for other etiologies. In addition, the presence of a pulse-synchronous rushing sound may require additional imaging to exclude vascular disorders. Otoscopy
An examination of the external ear canal and tympanic membrane performed by a medical doctor, otolaryngologist, or audiologist using an otoscope, a visual instrument inserted into the ear. This also allows some inspection of the middle ear through the translucent tympanic membrane. Tympanometry
A test administered by a medical doctor, otolaryngologist or audiologist of the tympanic membrane and middle ear function using a tympanometer, an air-pressure/sound wave instrument inserted into the ear canal.
Examples of sociocusis-related stimuli are the continuous noises from traffic, home appliances, music, television, and radio. The accumulated exposure to these noises over many years can lead to a condition similar to pure presbycusis. Nosocusis
Nosocusis factors are those that can cause hearing loss, which are not noise-based and separate from pure presbycusis. They may include:
Ototoxic drugs: Ingestion of ototoxic drugs like aspirin may hasten the process of presbycusis. vascular degeneration
Atherosclerosis: May diminish vascularity of the cochlea, thereby reducing its oxygen supply. Dietary habits: Increased intake of saturated fat may accelerate atherosclerotic changes in old age. Smoking: Is postulated to accentuate atherosclerotic changes in blood vessels aggravating presbycusis. Diabetes: May cause vasculitis and endothelial proliferation in the blood vessels of the cochlea, thereby reducing its blood supply. Hypertension: causes potent vascular changes, like reduction in blood supply to the cochlea, thereby aggravating presbycusis.However, a recent study found that diabetes, atherosclerosis and hypertension had no correlation to presbycusis, suggesting that these are nosocusis (acquired hearing loss) factors, not intrinsic factors. Pathophysiology
Examples of microscopic changes seen in this condition are hair cell degeneration of the cochlea and giant stereociliary degeneration. There are four pathological phenotypes of presbycusis:

Sensory: characterised by degeneration of the organ of Corti, the sensory organ for hearing. Located within the scala media, it contains hair cells with stereocilia, which extend to the tectorial membrane. The organs outer hair cells play a significant role in the amplification of sound and is extremely sensitive to external and internal factors.