Understanding What Are Bad Frequencies for Humans?

September 21, 2025 •

5 min read

A 2016 study found that infrasound at frequencies around 7 Hz can contribute to symptoms of 'sick building syndrome,' including nausea and dizziness. This highlights that harmful frequencies for humans are not limited to loud noise, but include inaudible vibrations and electromagnetic fields, which all pose distinct health risks.

Quick Summary

Harmful frequencies for humans exist across the spectrum, from inaudible infrasound and ultrasound to powerful electromagnetic fields, with the specific risk depending heavily on amplitude, duration, and exposure type. These exposures can lead to a range of effects, including disorientation, nausea, hearing damage, and neurological changes.

Key Points

Infrasound (Below 20 Hz): Can induce anxiety, nausea, and disorientation by causing body parts, like organs and eyes, to resonate when exposed to high amplitudes.
High-Intensity Audible Sound (20 Hz–20 kHz): The primary risk is volume (decibels), with prolonged exposure above 85 dB causing cumulative hearing damage and acute exposure above 140 dB risking immediate and permanent harm.
Ultrasound (Above 20 kHz): Though inaudible, high-intensity ultrasound, particularly in occupational settings, can transfer mechanical energy to the body, causing symptoms like headaches and fatigue.
Electromagnetic Frequencies (EMF): Non-ionizing EMF primarily causes tissue heating at high power, while the effects of low-level, chronic exposure remain a subject of debate and ongoing research.
Amplitude and Duration are Key: Harm is determined not just by frequency, but critically by the intensity (power) of the exposure and the length of time an individual is subjected to it.

Exploring the Spectrum of Harmful Frequencies

The idea of "bad frequencies" for humans is a complex topic that extends far beyond a simple chart of dangerous tones. The risks are not determined by frequency alone, but by a combination of factors, including intensity (decibels for sound, power for EMF), duration, and individual susceptibility. Potential hazards exist across the vibrational and electromagnetic spectrum, affecting us in different ways.

The Silent Threat: Infrasound (Below 20 Hz)

Infrasound refers to sound waves with frequencies below the typical human hearing range of 20 Hz. While inaudible, these powerful, low-frequency vibrations can have a significant impact on human physiology. They are generated by natural phenomena like earthquakes, strong winds, and ocean waves, as well as man-made sources like machinery, wind turbines, and traffic.

Body Resonance: The human body has several natural resonance frequencies. The abdominal cavity, for instance, resonates around 7-12 Hz, while the eyes resonate at approximately 45 Hz. Exposure to powerful infrasound at or near these frequencies can cause the corresponding body part to vibrate, leading to severe discomfort.
Health Effects: Symptoms associated with infrasound exposure include nausea, fatigue, malaise, anxiety, blurred vision, dizziness, and erratic breathing. High-intensity infrasound (above 120 dB) can even cause internal organ damage and, in extreme cases, be lethal.
Psychological Impact: Some research suggests infrasound can induce feelings of dread, unease, and disorientation, with some studies exploring its potential role in generating paranormal-like experiences in controlled settings.

The Auditory Danger Zone: Audible Frequencies (20 Hz to 20,000 Hz)

Within the human hearing range, the primary risk is volume, measured in decibels (dB), rather than frequency itself. Prolonged or intense exposure to loud noise can cause permanent hearing damage.

Loud Noise Effects: The World Health Organization (WHO) recommends limiting exposure to noise above 85 dBA over an 8-hour period to prevent hearing loss. A single exposure to a very loud impulse noise above 140 dBP, like a firecracker or a gunshot, can cause immediate and permanent damage.
High-Intensity Dangers: Sound levels exceeding 150 dB can rupture eardrums and damage internal organs. Levels above 185 dB can cause lethal internal injuries, although such extreme amplitudes are rare and typically occur only during events like massive explosions.
Cumulative Impact: Even moderate noise exposure over a long period can contribute to health problems like tinnitus, increased blood pressure, cardiovascular issues, sleep disturbance, and heightened stress levels.

The Edge of Perception: Ultrasound (Above 20,000 Hz)

Ultrasound refers to sound waves with frequencies above the human hearing range. While not audible, high-intensity ultrasound can still affect the body.

Medical Applications: Therapeutic ultrasound is used in medicine, but these applications are controlled and targeted. High-power, uncontrolled exposure, however, can be harmful.
Health Concerns: Occupational exposure to high-intensity ultrasound from industrial equipment has been linked to fatigue, headaches, dizziness, and nausea in workers, even at levels they cannot hear. The effects are often due to the transfer of vibrational energy to the body.

The Invisible Energy: Electromagnetic Frequencies (EMF)

Electromagnetic frequencies (EMF) are a different type of radiation, not sound waves. They are classified as either ionizing or non-ionizing, with very different effects on human health.

Ionizing Radiation: High-frequency EMF, such as X-rays and gamma rays, is powerful enough to knock electrons from atoms, causing direct cellular damage and increasing cancer risk. This is why precautions like lead shielding are used during medical imaging.
Non-Ionizing Radiation: Low-frequency EMF from sources like power lines (Extremely Low Frequency or ELF), radio waves, microwaves, and Wi-Fi networks is not powerful enough to ionize atoms. The primary, well-established biological effect of high-intensity exposure is heating of biological tissue. The potential for non-thermal biological effects at low levels is a subject of ongoing scientific debate, with research focusing on possible neurological, reproductive, and genotoxic effects.
RF Fields and SAR: For radiofrequency (RF) fields, the Specific Absorption Rate (SAR) measures the rate at which energy is absorbed by the body. High SAR values can cause tissue heating. Regulations exist to limit SAR levels from devices like mobile phones to prevent harmful thermal effects. You can learn more about the science of RF fields from authoritative sources like Health Canada's Safety Code 6 guidelines: Limits of Human Exposure to Radiofrequency Electromagnetic Energy in the Range of 3 kHz to 300 GHz.

Resonance and Exposure Factors

Resonance plays a critical role in how sound and vibration affect the body. When an external frequency matches the natural frequency of a body part, the vibration can be amplified, leading to disproportionate effects. Beyond frequency, the following factors are crucial:

Amplitude (Intensity): The sheer power of the frequency is often the most significant factor. Low frequency at high amplitude is far more dangerous than the same frequency at low amplitude.
Duration of Exposure: Chronic exposure to even moderate levels of certain frequencies can accumulate over time, leading to health issues like cumulative hearing loss or sleep disruption.
Source Proximity: The closer you are to the source of the frequency, the higher the intensity of exposure. For example, using a power tool versus being near a distant power line.

Mitigation and Protection Strategies

Protecting yourself from harmful frequencies involves minimizing exposure to high-intensity sources.

Reduce Noise Exposure: Use hearing protection (earplugs, earmuffs) when working in noisy environments or attending loud concerts. Follow safe listening practices with headphones by keeping the volume at a moderate level.
Be Aware of Infrasound Sources: If you experience persistent symptoms like dizziness or nausea in a specific location, consider potential sources of infrasound, such as poorly maintained machinery or HVAC systems.
Use EMF-Emitting Devices Wisely: Maintain distance from Wi-Fi routers and other EMF sources where possible. Use hands-free devices for phone calls to reduce close-range exposure to the head.
Prioritize Quality Equipment: In occupational settings, ensure machinery and tools are properly maintained to minimize excessive vibration and noise. Consider the noise ratings of household appliances.

Comparison Table: Harmful Frequency Types


Frequency Type	Example Sources	Primary Risk Factor	Example Health Effects
Infrasound	Wind turbines, large machinery, storms, traffic	High amplitude at low frequency; mechanical resonance	Nausea, dizziness, anxiety, organ damage (at high intensity)
Audible Sound	Concerts, power tools, traffic, music devices	High decibel (loudness) level; duration	Hearing loss, tinnitus, cardiovascular stress, sleep disruption
Ultrasound	Industrial cleaners, some medical imaging, pest control	High amplitude at high frequency; mechanical stress	Headaches, fatigue, nausea
Electromagnetic (Non-Ionizing)	Power lines, Wi-Fi, cell phones, microwaves	High power leading to thermal effects; ongoing debate on non-thermal	Tissue heating, potential neurological changes, cancer risk (debated)
Electromagnetic (Ionizing)	X-rays, gamma rays	High energy leading to ionization	Cellular damage, cancer

Conclusion

The impact of frequencies on human health is not a single issue but a diverse set of concerns ranging from mechanical vibrations to electromagnetic radiation. While specific, high-intensity sound frequencies can cause immediate, acute damage, chronic exposure to low-level frequencies, both audible and inaudible, poses cumulative risks to our well-being. By understanding the different types of harmful frequencies and the factors that influence their impact, individuals can take proactive steps to minimize exposure and protect their health. From wearing hearing protection to being mindful of our proximity to various man-made technologies, informed choices are key to mitigating these often-unseen environmental threats.

Frequently Asked Questions

There is no single "most dangerous" frequency range, as danger depends on the type, amplitude, and duration of the exposure. High-intensity infrasound (below 20 Hz) can disrupt internal organs through resonance, while high-amplitude audible sound can cause permanent hearing loss. High-energy ionizing EMF (like X-rays) is the most dangerous form of radiation but is controlled by strict safety regulations.

Exposure to infrasound from wind turbines is a concern, particularly at high amplitudes. Some individuals report symptoms like headaches, dizziness, and anxiety, though the link and severity are subjects of ongoing scientific debate.

High-intensity ultrasound exposure, common in some industrial settings, can transfer mechanical energy to the body, potentially causing headaches, fatigue, nausea, and tinnitus, even though the sound is inaudible to humans.

Cell phones and Wi-Fi emit non-ionizing electromagnetic frequencies. The primary established risk is tissue heating at very high power, which is why devices have SAR limits. While some studies explore potential non-thermal biological effects, the evidence is not conclusive and the topic remains controversial.

When a high-amplitude frequency matches a body part's natural resonant frequency, the vibration can be amplified. For instance, infrasound near 7-12 Hz can cause abdominal vibration, leading to discomfort and potentially damage at high intensity.

To protect against audible noise pollution, use hearing protection like earplugs or earmuffs in loud environments, limit exposure time, and maintain a safe volume level when using personal listening devices. Many jurisdictions also have noise ordinances that can be enforced.

While theoretically possible at extreme amplitudes, it is practically impossible to create sound waves powerful enough to be instantly lethal in an open environment. However, sustained exposure to sound above 185 dB can cause fatal internal injuries, typically only occurring during events like powerful explosions.