Sensory Presbycusis: Age-related Hearing Loss
Sensory Presbycusis, also known as age-related hearing loss, is a condition that affects individuals as they get older. It is caused by the gradual reduction in the number of nerve cells in the cochlea and auditory pathways. These nerve cells are responsible for transmitting sound signals to the brain.
Throughout life, the number of nerve cells naturally decreases. However, when the number of nerve cells in the cochlea and auditory pathways drops to 50% or less, individuals are said to have sensory presbycusis. The effects of this condition are not usually noticeable until later in life.
It is believed that the severity of sensory presbycusis may be genetically predetermined, meaning that some individuals may be more prone to experiencing more severe symptoms than others.
Unlike other types of age-related hearing loss, sensory presbycusis specifically affects speech discrimination. This means that individuals with sensory presbycusis may have difficulty understanding and distinguishing speech sounds, making conversations and communication more challenging.
Understanding Metabolic Presbycusis
Metabolic presbycusis, also known as stria presbycusis, is a condition characterized by the atrophy of the stria vascularis. The stria vascularis plays a crucial role in supplying blood to the inner ear and maintaining the cochlea’s balance. When this structure deteriorates, it affects the entire cochlea, resulting in equal impact on different frequencies of sound. However, it does not significantly affect speech discrimination. It is believed that this progressive form of presbycusis may have a hereditary component.