About

This utility is a high-fidelity signal generator designed to assess the upper and lower limits of audible perception. Unlike standard online videos or MP3 files, which suffer from compression algorithms that cut off frequencies above 16,000 Hz, this tool utilizes the Web Audio API to generate mathematically pure sine waves directly in your browser. This ensures that the sound wave is free from digital artifacts and harmonic distortion.

Hearing degradation, particularly in the high-frequency range, is a natural biological process known as presbycusis. By the age of 25, most adults lose the ability to hear frequencies above 17,000 Hz. This tool allows for precise unilateral testing (Left/Right isolation) to identify asymmetrical hearing loss, which can be an early indicator of sensorineural issues or acoustic trauma.

Formulas

The generation of the test tone relies on the sinusoidal oscillation formula used in digital signal processing. The frequency f determines the pitch, while the amplitude A determines the loudness.

{

y(t) = A ⋅ sin(2πft)λ = vf

Where λ (lambda) is the wavelength, v is the speed of sound (≈ 343 m/s in air at 20°C), and f is the frequency in Hertz.

Reference Data

Frequency (Hz)	Sound Reality & Context	Wavelength (λ)	Typical Age Limit
20 − 60	Sub-bass. Felt more than heard. Thunder, heavy machinery.	17 m	Universal
250	Middle C (approx). Fundamental frequency of female speech.	1.37 m	Universal
1,000	Reference Tone. Calibration standard.	34 cm	Universal
4,000	Most sensitive range of human ear. Baby crying.	8.5 cm	Universal
8,000	Sibilance in speech (s, sh, f). Cymbals.	4.2 cm	60+
12,000	CRT TV whine (old/pal format). High-hat sparkle.	2.8 cm	50
15,000	"Mosquito" devices used to deter loitering teens.	2.2 cm	40
17,400	The "Teen Buzz" ringtone. Invisible to most adults.	1.9 cm	24
20,000	Theoretical limit of human hearing. Bat echolocation.	1.7 cm	18

Frequently Asked Questions

This is likely normal presbycusis. As we age, the hair cells at the base of the cochlea (responsible for high frequencies) wear out. If you are under 20 and cannot hear this, check your equipment - many standard laptop speakers cannot physically produce these frequencies.

Yes. Room acoustics, standing waves, and ambient noise significantly affect speaker accuracy. High-quality closed-back headphones or IEMs (In-Ear Monitors) provide the most reliable isolation and frequency response for this test.

Any sound played at high decibel levels can cause damage. We have built-in limiters, but high-frequency sounds can be deceptive; you might not "hear" them loudly, but the sound pressure can still fatigue the ear. Always start with the volume at 10%.

This is called a "transient" or "pop." It happens when a sound wave stops instantly while its amplitude is not at zero crossing. Our tool uses a "Linear Ramp" to fade the volume out over 0.1 seconds to minimize this, but system latency can sometimes still cause minor artifacts.