How Many Decibels Is Harmful? Table With 30–140 dB Examples

Everyone is surrounded by sound all day long. But when is it just noise, and when does it damage your hearing? The short answer: sound can become harmful from about 80 decibels. How harmful it is depends on how loud it is and how long you are exposed.

The table below shows how loud everyday sounds are and how long you can be around them without hearing protection before you reach your daily dose.

The safe time follows the rule of thumb that is also used at work: 80 dB(A) for 8 hours, and every 3 dB louder halves the time. So at 83 dB that is 4 hours, at 86 dB 2 hours, at 89 dB 1 hour and at 92 dB half an hour. The examples are guide values. How loud something is at your ear depends on your distance from the source and on the room. On a motorcycle, it is mainly the wind that drives up the noise under your helmet; how to protect yourself and still hear music and navigation is explained in music and navigation on a motorcycle.

When is sound harmful?

Your inner ear contains hair cells that turn sound vibrations into signals for your brain. Too much sound overloads those hair cells. After an evening in loud noise, you may temporarily hear less or have ringing in your ears. If that happens often, the hair cells are damaged for good. They do not grow back, so the hearing loss is permanent. Tinnitus, a beep or hiss that won’t go away, can also develop this way.

Whether sound causes damage depends on two things together: how loud it is and how long you are exposed. That is your noise dose. This is why a working day at 85 dB can be just as harmful as fifteen minutes at the front of a concert. Above 100 dB it goes fast: you reach your daily dose within minutes. The pain threshold lies around 120 to 130 dB, and with even louder bangs, such as a gunshot at close range, a single exposure can cause permanent damage.

How does the decibel scale work?

Decibels are not an ordinary scale where 100 is twice as much as 50. The scale is logarithmic: every 10 dB more means ten times as much sound energy, and sounds roughly twice as loud to your ear. Every 3 dB more already doubles the sound energy, even though you can barely hear the difference.

So 120 dB is not twice as loud as 60 dB: it contains a million times as much sound energy. And that is why the safe time halves with every 3 dB.

What does dB(A) mean?

Your ear is not equally sensitive to all pitches. You hear mid-range tones, around 1,000 to 5,000 hertz, best, and very low tones much less. A sound level meter takes that into account with an A-weighting filter. Low tones then count for less, so the measurement matches what your ear experiences more closely. The result is called dB(A). That is why noise limits are usually expressed in dB(A).

For short, loud bangs, such as a hammer blow or a shot, a C-weighting filter is used that includes almost all of the low tones. That gives dB(C). At work, separate peak values apply to these. A firework bang is a peak like this too; read what you can do about it in earplugs for fireworks.

How many dB is annoying?

Annoying and harmful are two different things. Sound can damage your hearing without bothering you, like music you enjoy. And sound can be very annoying without affecting your hearing, like a ticking radiator or the neighbours’ bass.

Whether you find a sound annoying depends less on the number of decibels than on the type of sound, the time of day and you. Most people find sound they can’t control, irregular sound and sound in the evening or at night disturbing. Noise annoyance can lead to poor sleep, stress and trouble concentrating.

The WHO has set guide values for environmental noise. For road traffic, the WHO recommends staying below 53 dB outside the home, averaged over the whole day and night, and below 45 dB at night. Above that, annoyance and health complaints increase noticeably. Those values are far lower than the 80 dB at which hearing damage starts.

With noise from neighbours, there is usually no fixed decibel limit: what matters is whether the noise is reasonably considered a nuisance. The rules differ per country and often per town. If you can’t work it out together, a mediation service, which many towns offer, can help.

At work: the legal limits

Legal limits apply in the workplace. They are based on your daily dose over an 8-hour working day:

• 80 dB(A): your employer must make hearing protection available and inform you about the risks.
• 85 dB(A): you are required to wear hearing protection.
• 87 dB(A): the exposure limit value, measured in the ear, so with hearing protection in. The level must never go above it.

These are the EU minimum rules (Directive 2003/10/EC). Every EU country has written them into its own law, and some countries are stricter, so check your national rules.

If you work above these levels, you are entitled to a hearing test. Assessing and measuring the noise is your employer’s job, as part of the risk assessment. We carry out this kind of sound measurement on site with a class 1 sound level meter. All the rules, including the peak values and who pays for what, are in when is hearing protection mandatory.

For people who work in noise there are dedicated work earplugs, and for construction hearing protection for construction. Which professions run the most risk is shown in our overview of jobs with a high risk of hearing damage.

Music in your free time: no European standard

For concerts, clubs and festivals there is no EU standard. Each country, and sometimes each region or town, sets its own rules, and many have none at all. Internationally, the WHO set a guideline in 2022, the Global Standard for Safe Listening Venues and Events: a maximum of 100 dB LAeq averaged over 15 minutes, live monitoring of the sound level, and hearing protection available for visitors.

National examples vary. In the Netherlands, for example, the music industry has agreed to a maximum of 103 dB(A) averaged over 15 minutes. Flanders (Belgium) allows up to 100 dB(A) over 15 minutes, and in Germany the DIN 15905-5 standard uses 99 dB(A) averaged over 30 minutes. Other countries set their own limits, and many have none.

For comparison: at 103 dB, according to the rule of thumb, you reach your daily dose after about 2.5 minutes. A concert or festival lasts many times longer. With festival earplugs with a music filter, the music stays clear while the volume at your eardrum drops to a safe level.

Measure it yourself

Want to know how loud it is somewhere? A decibel app on your phone gives a reasonable indication. On an iPhone these apps are usually more reliable than on Android, because the microphones vary less between devices. Hold the phone in the open, not in your pocket, and look at the average over a few minutes rather than the highest peak.

No app to hand? Then there is a simple rule of thumb: if you have to raise your voice to be understood by someone a metre away, the sound is probably above 80 dB. For a measurement that counts at work, you need a calibrated sound level meter.

You will find more practical tips to protect your ears in prevent hearing damage. And if you want to know how sound actually works, from vibration to pitch, read what is sound.