Permitted decibels: what you need to know about noise levels

Noise is part of our daily lives. There is nothing we can do to eliminate it entirely. We hear it in traffic, in conversations, and in the devices we use. Sometimes we notice it and other times it goes unnoticed, but its impact on our well-being is undeniable. Permitted decibel levels are a matter of regulation. But they are also a way of striking a balance between comfort and functionality in the spaces where we live and work.

Defining these limits allows us to create better environments. Environments where communication flows, rest is restorative and daily activities are not disrupted. Conditioning a space to have the right noise level has a positive impact on the experience of those who inhabit it. Furthermore, it prevents long-term health problems.

What is a decibel?

The decibel (dB) is the unit used to measure sound intensity. Unlike other units, decibels do not increase in a linear fashion; every time the sound level rises by 10 dB, it actually becomes ten times louder. This helps us understand how noise affects different environments and ensures that sound levels are appropriate for each situation.

To measure these decibels, sound level meters are used. These are special tools that measure sound pressure in a specific location. Thus, they provide precise data on the noise level in the environment. These devices operate using a highly sensitive microphone that detects variations in air pressure caused by sound waves.

The captured information is converted into measurable and comparable data. This allows us to determine whether an environment complies with the decibel limits set by current regulations.

Sound Levels

Sound levels can be categorized as follows:

• 30 dB: A quiet environment, equivalent to a whisper or nighttime noise in a quiet room.
• 50 dB: Normal conversation in an office or background noise in a home.
• 70 dB: A noisy environment such as a street with moderate traffic.
• 85 dB or higher: A sound level that, with prolonged exposure, can cause hearing damage (such as the sound of a lawnmower or a running motorcycle).
• 100 dB or higher: Noise from a nightclub or a live concert, which can cause hearing loss within a few hours without proper protection.

Using acoustic treatment technologies allows noise levels to be adjusted within recommended parameters. For example, sound-absorbing panels and acoustic barriers reduce noise without affecting the functionality of the space.

Effective sound management in offices, commercial, and industrial spaces improves comfort and protects the hearing of those who work or live there.

Why is there a limit on permissible decibels?

Excessive noise is not just a nuisance; it is also a key factor affecting concentration, work performance, and rest. Studies have shown that noise levels exceeding 50 dB in workspaces reduce concentration by up to 20%, while prolonged exposure to noise levels above 85 dB can lead to chronic stress and affect cardiovascular health.

Regulating permissible decibels aims to reduce noise pollution, ensuring more comfortable and functional spaces. This is why good acoustics are important. In reality, it’s not just about minimizing noise. It’s also about creating spaces where sound is balanced and appropriate for the activity taking place.

• Acoustic treatment solutions include:
• Absorptive panels.
• Acoustic diffusers.

Spatial configurations that optimize sound propagation. This helps reduce reverberation and background noise. At the same time, it maintains the quality of communication or the functionality of the environment.

The link between health and permissible decibel levels

Constant exposure to very loud noises or sounds can cause various types of damage to the ears. In some cases, this damage may be irreversible. For example, a noise level of 85 dB can cause hearing loss if exposure is prolonged. This is known as noise-induced hearing loss (NIHL) and affects people who work in noisy environments without adequate protection. It can also affect people who regularly visit noisy leisure venues, such as nightclubs or bars.

The human ear is designed to pick up a wide range of frequencies, but its sensitivity varies depending on the intensity of the sound. A sudden, extremely loud noise, such as an explosion (exceeding 120 dB), can cause immediate and permanent damage to the auditory system. However, the most common danger lies in prolonged exposure to high levels.

The effects of exceeding the decibel limits recommended for hearing health are not limited to hearing loss alone. Many people exposed to high sound levels develop tinnitus. This is a sensation of constant ringing in the ears that can become chronic (NIH, 2023).

Furthermore, several studies have already shown that prolonged exposure to noise is linked to an increase in:

• Stress.
• Sleep disorders.
• Changes in blood pressure (which can lead to cardiovascular problems).

How should permissible decibel levels be regulated?

To mitigate these risks, regulations have been introduced that set limits on permissible decibel levels in different settings. In the workplace, for example, the World Health Organisation (WHO) recommends limiting exposure to 80 dB for a maximum of 40 hours per week (WHO, 2024).

In leisure venues such as concerts and nightclubs, regulations vary, but in many countries limits of 100 dB with restricted exposure times have been established.

Acoustic treatment is a key solution for reducing the impact of noise without compromising the functionality of a space. Measures such as the installation of sound-absorbing panels, floating floors and acoustic barriers can significantly reduce the propagation of sound. This helps to regulate permitted decibel levels without the need for total soundproofing.

Not only does it improve the acoustic experience of an environment, but it also contributes to the health and well-being of those in these spaces.

Permissible decibels depending on the context

Every environment has specific requirements in terms of noise levels. Proper noise management is key to maximising efficiency and quality of life in each of them.

Workplace

In the industrial and office sectors, noise levels must be tailored to the activities carried out. According to ergonomic studies, office environments should be kept below 50 dB to aid concentration, whilst in factories the limit is usually set at 85 dB with mandatory hearing protection.

Acoustic treatment in these spaces aims to minimise noise propagation through solutions such as sound-absorbing panels and spatial designs that reduce reverberation.

Regulations on permitted decibel levels in Spain

There are specific regulations governing permitted decibel levels in Spain. These are set out in the Noise Act and also in certain local by-laws, which specify more detailed limits. These limits vary depending on the land use. In residential areas, for example, the limit ranges from 40–55 dB during the day and 30–45 dB at night. In industrial areas, however, the limits are more flexible, allowing up to 75 dB during working hours.

Compliance with these regulations is important to ensure healthy environments. Some companies specialising in acoustic treatment, such as Ideatec, offer solutions to adapt all kinds of spaces. This significantly improves the conditions of these spaces. Ultimately, considering the installation of tools to improve a space’s acoustics is an investment in general well-being. A balance must be struck between everyday noise, sound and people’s comfort.

References

NIH. (2023). Tinnitus. NIDCD.

WHO. (2024). Deafness and hearing loss: Safe listening. Who.int.