Humans can detect sounds from about 20 Hz to 20,000 Hz (20 kHz), though most adults never actually hear that full range. The upper limit drops significantly with age, and by adulthood, many people top out around 15,000 to 17,000 Hz. Your ability to hear across this spectrum depends on your age, sex, noise exposure history, and the remarkable anatomy of your inner ear.
The 20 Hz to 20 kHz Range
The textbook answer for human hearing is 20 Hz to 20 kHz. The low end, 20 Hz, is a deep rumble you feel almost as much as hear, like the lowest notes of a pipe organ or a heavy diesel engine idling. The high end, 20 kHz, is an ultra-thin, piercing tone that most children can hear but few adults can. Infants actually hear slightly above 20 kHz, then gradually lose access to those highest frequencies as they grow.
Within that range, your ears are not equally sensitive to all frequencies. The ear is most sensitive between roughly 2,000 and 5,000 Hz, a sweet spot created by the natural resonance of the ear canal. This is the frequency band where consonants in speech live, where a baby’s cry lands, and where alarm signals are typically designed to fall. A sound at 3,000 Hz doesn’t need to be nearly as loud to be heard as the same sound at 100 Hz or 15,000 Hz.
How Your Inner Ear Sorts Frequencies
The cochlea, the snail-shaped structure in your inner ear, is essentially a frequency-sorting machine. It contains a strip of tissue called the basilar membrane, lined with thousands of tiny hair cells. These hair cells are arranged by frequency: the base of the cochlea (near the entrance) responds to high-pitched sounds, while the far end (the apex) responds to low-pitched ones. This layout means that when a sound enters your ear, different parts of the cochlea vibrate depending on the pitch.
The physical structure of these hair cells changes along the length of the cochlea to match their frequency job. At the low-frequency end, each hair cell has a tall bundle of around 50 tiny bristles called stereocilia. At the high-frequency end, the bundles are shorter but far denser, containing more than 300 stereocilia. The basilar membrane itself gets stiffer toward the high-frequency base. All of these gradients work together to make each section of the cochlea finely tuned to its assigned pitch, giving you the ability to distinguish thousands of different tones.
How Age Shrinks Your Range
Age-related hearing loss, called presbycusis, always starts at the top of your frequency range and works its way down. Research tracking hearing thresholds across age groups shows a clear pattern: people in their 20s typically begin losing sensitivity at frequencies around 12 kHz and above. By the 40s, hearing loss often starts appearing at 8 kHz and above. Even people with perfectly normal results on a standard hearing test (which only measures up to 8 kHz) show measurable high-frequency loss by their 30s. One study found that 16% of people in their 20s already had some loss above 8 kHz, and by the 30s, that figure reached 50%. By the 40s, it was universal.
This is why the “mosquito ringtone,” a tone around 17 kHz, works as a test of auditory age. Teenagers hear it easily. Most people over 40 cannot. The hair cells at the base of the cochlea, responsible for the highest frequencies, are the most vulnerable to cumulative wear. Once those cells die, they don’t regenerate.
Differences Between Men and Women
At frequencies above 1,000 Hz, men in their 20s already have measurably worse hearing than women of the same age. This gap persists through middle age, with men losing high-frequency sensitivity faster. The difference likely reflects a combination of occupational noise exposure (historically more common in men) and possible hormonal or anatomical factors. Interestingly, the gap disappears at both extremes of the age spectrum: very young children and people in their 80s and 90s show no meaningful sex-based differences, suggesting that biology and environment converge over time.
Where Noise Damage Hits First
Loud noise doesn’t destroy your hearing evenly. It targets a specific frequency band first: around 4,000 Hz. On a hearing test, noise-induced hearing loss shows up as a characteristic dip (audiologists call it a “notch”) at 4 kHz, with better hearing on either side. This notch is a reliable clinical marker for noise damage and is strongly associated with exposure to firearms, industrial machinery, and loud music.
The reason 4 kHz is so vulnerable involves the anatomy of the ear canal. The canal amplifies sounds around 3,000 to 4,000 Hz due to its resonance properties, meaning those frequencies hit the inner ear harder than others. Over time, this concentrated energy damages the hair cells responsible for that range. A notch sometimes also appears at 6 kHz, but research shows this is far less specific to noise exposure and less useful as a diagnostic sign.
Hearing Below 20 Hz
The 20 Hz lower boundary isn’t as firm as it sounds. Frequencies below 20 Hz, called infrasound, can be perceived by humans if they’re loud enough. The catch is that the required volume is enormous. An 11 Hz tone needs to reach roughly 95 dB SPL (comparable to standing near a running lawnmower) just to hit the threshold of detection. An 8 Hz tone requires even more.
What makes infrasound perception especially interesting is that the brain appears to process these frequencies even when you can’t consciously detect them. In one experiment, researchers presented 8 Hz and 11 Hz tones at levels right at each person’s sensation threshold, and nine out of ten subjects produced measurable brain responses to the 8 Hz tone. Two subjects even showed brain activity when the infrasound was played 5 dB below their conscious threshold, at a level where they could only correctly identify the tone about 57% of the time (barely better than guessing). Environmental infrasound from wind turbines, traffic, and industrial equipment often falls in this range and is a common source of complaints, even when the sound isn’t consciously “heard.”
Practical Frequency Landmarks
- 85–255 Hz: The typical range of a human speaking voice’s fundamental frequency, lower for men, higher for women and children.
- 250–500 Hz: The body of most musical instruments and the warmth in a voice.
- 2,000–5,000 Hz: Peak sensitivity zone. Speech clarity, the crack of a snare drum, a smoke alarm’s beep.
- 4,000 Hz: The frequency most vulnerable to noise damage.
- 8,000–12,000 Hz: The range where age-related loss typically first becomes measurable.
- 15,000–17,000 Hz: Practical upper limit for most adults.
- 20,000 Hz: Theoretical upper limit, accessible mainly to children and teenagers.