Hearing allows humans to perceive sound, which is vibrations traveling through a medium. The ability to detect these sounds, particularly across different frequencies, changes throughout a person’s life. The range of frequencies an individual can hear often narrows with increasing age.
What Sound Frequency Means
Sound travels in waves, and frequency describes how many of these waves pass a point in a given amount of time. This measurement is expressed in Hertz (Hz). Frequency directly relates to the pitch of a sound. A higher frequency corresponds to a higher-pitched sound, such as a whistle or a bird’s song. Conversely, a lower frequency produces a lower-pitched sound, like the deep rumble of a drum or a bullfrog’s croak.
Typical Human Hearing Range
A young, healthy human ear can typically perceive a broad spectrum of sounds. This range commonly spans from approximately 20 Hz to 20,000 Hz (or 20 kHz). Sounds below 20 Hz are known as infrasound, while those above 20 kHz are termed ultrasound, and neither is typically audible to humans. The human auditory system is most sensitive to frequencies between 2,000 and 5,000 Hz.
How Hearing Changes Over Time
The ability to hear certain frequencies changes as people age, a condition known as presbycusis, or age-related hearing loss. This decline usually begins with higher frequencies. For example, a person in their twenties might hear up to 17,000 Hz or more, but this can decrease to around 16,000 Hz by their thirties. By the time an individual reaches their 50s, their hearing range may typically decline to approximately 12,000 Hz. The loss of high-pitched sounds can make speech difficult to understand, particularly in noisy environments.
This progressive and irreversible sensorineural hearing loss often begins subtly. It frequently becomes noticeable after the age of 50, affecting about one in three people over 65. The highest frequency sounds are usually affected first, with lower frequencies becoming impacted as the condition advances.
Why Hearing Declines with Age
Age-related hearing loss is primarily linked to changes within the inner ear. The tiny hair cells located in the cochlea, which are responsible for converting sound vibrations into electrical signals for the brain, can become damaged or die over time. Unlike some other cells in the body, these hair cells do not regenerate, leading to permanent hearing loss.
Several other factors also contribute to hearing decline. Cumulative exposure to loud noises throughout a lifetime can accelerate damage to these delicate hair cells. Genetics plays a role, as some individuals are more predisposed to age-related hearing loss. Certain medical conditions, such as diabetes and cardiovascular disease, and some medications can also contribute.
Keeping Your Hearing Healthy
Protecting hearing throughout life can help slow down age-related decline. Avoiding prolonged exposure to loud noises is a preventive measure. When in noisy environments, such as concerts or workplaces with machinery operating above 85 decibels, using hearing protection like earplugs or earmuffs is advisable. Taking short breaks from loud noise every 15 minutes and giving ears at least 18 hours to recover after significant exposure can also be beneficial.
Regular hearing check-ups can help detect early signs of hearing loss. Maintaining overall health through exercise and managing conditions like diabetes and high blood pressure supports the auditory system. These steps contribute to preserving hearing ability for as long as possible.