[Column] Why do sirens differ from country to country?—Design philosophy for warning sounds created by sound environment and social structure
Column en Siren Sound![[Column] Why do sirens differ from country to country?—Design philosophy for warning sounds created by sound environment and social structure](/../assets/images/column-siren-sound.webp)
The sound of sirens is “culture”
| Text: mmr | Theme: The siren sounds of each country are not just differences in volume, but are the product of design ideas that are closely linked to living environments, travel distance, and music culture. |
A siren sounds somewhere in the city. This sound is not just a warning of an emergency situation, but is actually a ““designed sound”’ that reflects the country”s lifestyle and sound environment. It’s no coincidence that the volume, frequency, and pattern of sirens vary from country to country. This is because the assumptions about where and how people listen to sound are different.
For example, in Japan, many people live in relatively compact urban structures, and it is common to walk or use public transportation to get around. On the other hand, in a vast country like the United States, long journeys by car are commonplace, and the closed space inside the car becomes one of the main sources of daily noise.
This difference has a direct impact on siren design.
A siren is not just a warning sound, but a sound that reaches people and is designed to be optimized for the human living environment.
“How you hear” cannot be explained with just digitized bells
When talking about siren performance, we tend to focus on the “volume (decibel)”, but in reality, that alone is not enough. What matters is “in what environment” and “how it sounds.”
Generally speaking, emergency vehicle sirens have a sound pressure of approximately 100 to 120 decibels. However, this value is only an outdoor standard. In actual living spaces, the following factors greatly affect the arrival of sound.
・Sound insulation performance inside the car ・Car audio volume ・Housing insulation and soundproofing structure ・City noise level ・Reflection of road shapes and buildings
Particularly in recent years, cars are highly sound insulated, and in regions where there is a culture of playing music at high volume inside the car, simply increasing the volume may drown out the siren.
For this reason, sirens are not just a loud sound, but are designed to be a sound that penetrates the environment.
The essence of a siren is not its volume, but its design, which allows it to be perceived above environmental noise.
Long-distance migration and music culture in America
In the United States, the distances between cities are extremely long, and transportation by automobile is central to life. It is not uncommon for people to drive for more than an hour to commute or travel. As a result, the interior of a car has developed not just as a space for transportation, but also as a space for enjoying music.
Car audio culture is very strong, and it is common to play music at high volumes. This is also due to the prevalence of music genres that emphasize bass and treble, such as hip-hop and rock.
In such an environment, it is difficult to notice with a normal, monotonous warning sound. Therefore, American sirens have the following characteristics:
-Very high volume
- Frequency changes (Vienna, Yoop, etc.) ・Rhythmically modulating ・Designed to give a sense of direction
This ensures that it doesn’t get lost in the music and is immediately recognized by the driver.
A culture of long driving hours and loud music has led to the evolution of sirens into more aggressive and varied sounds.
Optimization of Japanese city structure and sirens
On the other hand, Japan’s cities are relatively dense, roads are narrow, and there are many pedestrians and bicycles. For this reason, the importance of sirens is placed on ““recognition at close range” and ““consideration of the surroundings” rather than reaching long distances.
Additionally, because Japanese homes are densely packed, excessive volume has a large impact on the living environment. As a result, Japanese sirens have the following characteristics.
・Relatively quiet volume ・Regular and easy-to-understand patterns ・Use of audio announcements ・Night volume control
Furthermore, sounds such as “An ambulance is passing by” have the role of helping people understand the situation even in environments where visual information is difficult to obtain.
Japanese sirens are ““sounds that make people understand’’ that are optimized with consideration to urban density and the living environment.
History and sound design in Europe
In Europe, many buildings are made of stone due to the influence of urban structures that have continued since the Middle Ages, and the sound reverberation characteristics are unique. For this reason, sirens are designed to use reflected sound to reach a wide range.
The reason why each country has a different sound pattern is to make it easier to identify people when they cross borders. For example, Germany uses a relatively simple pattern, while France uses a different rhythm.
Sounds are not just warnings, but also function as symbols to identify countries and regions.
European sirens have evolved within historical urban structures and cultural distinctiveness.
Differences in siren sound patterns in European countries
In Europe, the sound of a siren is not only designed to increase the volume or alert people, but also to provide important information for instantly identifying what type of emergency vehicle it is. Behind this is the legal system of each country and the long history of cities.
Germany: Standardized two-tone alternating pattern
German emergency vehicles commonly use an alternating two-tone pattern known as ““high-low.’’ This is clearly standardized, and switching frequencies creates a strong alert.
The characteristics are as follows.
・Alternately play two fixed frequencies ・Modulation is relatively simple -Easy to identify even at long distances
- Difficult to mix with other sounds
This simplicity is intentional, and has the advantage of allowing sound to travel unimpeded, even in highly reverberant urban environments. Additionally, in Germany, traffic regulations define the combination of a siren and a blue light as a clear signal for giving way, so the sound pattern must be clear enough to avoid misidentification.
The German siren is a sound that can be ““avoided without hesitation’’ through standardization and clarity.
France: Distinguishability through rhythm modulation
Unlike Germany, France uses sirens with more complex rhythmic changes. In particular, even the pattern called “2 tone” has variations in its cycle and tempo.
As for the characteristics.
・Cyclic but fast-paced ・Sound rises sharply ・Design that stands out amidst urban noise ・Slightly different depending on vehicle type and usage
In a high-density city like Paris, there is always a lot of noise, so moving sounds are more likely to attract attention than simple two-tone sounds. Therefore, there is a strong tendency for French sirens to be recognized by rhythm.
The French siren is a sound that is perceived as ““motion’’ amidst the noise of the city.
UK: Wild modulation and multiple modes
In the UK, a feature is that multiple siren modes can be used depending on the situation. Typical examples include ““wail,” ““yelp,” and ““hi-lo.’’
The roles of each are clearly separated.
・wail: alerting at a long distance (slow modulation) ・YELP: Short-range warning in urban areas (high-speed modulation) ・Hi-lo: Used at intersections and specific situations
This type of switching is based on the idea that the driver selects the optimal sound depending on the environment. Also, because the change in sound itself attracts attention, it is easier to recognize than a single pattern.
British sirens are ““manipulated sounds’’ that are optimized depending on the situation.
Italy: Strong argument for high frequencies
In Italy, relatively high-frequency sirens are characteristic, and emphasis is placed on clarity of sound. This is because there are many stone buildings in historic cities, and low frequencies are easily absorbed and diffused.
The characteristics are below.
・Strong treble range ・Sustained and extended sound ・Diffusion using echoes ・Designed to reach even in narrow alleys
Particularly in the old city, visibility is often obstructed, so the presence of sound is more important than the direction of the sound.
Italy’s siren is the “sound of existence” that penetrates the complex urban structure.
Northern Europe (Sweden/Norway): Contrast with silence
In the Nordic countries, sirens do not need to be overly complex, as normal environmental noise is relatively low. Instead, many designs are recognized for their contrast with silence.
As for the characteristics.
・Relatively smooth frequency change ・Sounds that are not overly aggressive ・Clearer presence than long-distance transmission ・Consideration of environmental impact
In addition, thorough controls have been put in place to control the volume at night.
The Nordic siren is a ““sound of difference’’ that stands out due to its contrast with silence.
Distinctiveness is a “result”
Taking these into account, the differences in sirens in each country are not simply designed to identify national borders, but rather are the result of optimization for each country’s urban structure, traffic culture, legal system, and sound environment.
As a result, when entering a neighboring country, people feel strange due to the difference in sounds, and it becomes possible to identify them.
In other words,
・The purpose of the design is “to ensure delivery in the country” ・As a side effect, “differences between countries become clearer”
This is the relationship.
The differences in sirens between countries are not intentional identifications, but rather ““sound dialects’’ that have arisen as a result of environmental adaptation.
Relationship between music environment and siren design
What is often overlooked in siren design is the ““everyday music environment.’’ The type of sounds people are normally surrounded by has a major influence on the design of warning sounds.
In environments where music is played at high volume, the siren needs to have a higher pitch and more modulation. On the other hand, in a quiet environment, excessive volume can have the opposite effect.
In other words, sirens are designed to fit into the ““interstice of everyday sounds.’’
Siren is designed not to compete with musical culture, but to fill a gap in it.
Technological evolution and the future of sirens
In recent years, the soundproofing performance of automobiles has further improved, and the spread of electric vehicles has reduced external noise. This change brings new challenges to siren design.
Traditional loud sirens alone are becoming insufficient, and the following technologies are beginning to be introduced.
・Direct notification to in-car speaker ・GPS-linked warning system ・Linkage with vision and vibration ・Directional speaker
As a result, the siren has evolved from a mere sound to an “information transmission system.”
Sirens started out as sounds and are now morphing into multisensory warning systems.
Chronology: Changes in siren and sound environment
Conclusion: Sirens are designed for “places they need to reach”
The difference in sirens is not simply a difference in specifications between countries. This comes from differences in assumptions about where people hear sounds and how they live their lives.
In a country with vast roads and a motorized society, there is a need for strong and changing sounds that can reach the enclosed interior of a car. In countries with densely populated cities, there is a need for sound that coexists with its surroundings and is reliably recognized.
Behind this, music culture and the everyday sound environment are closely related.
Sirens are a microcosm of society and part of the sound infrastructure.
The difference between sirens is not a difference in sound, but a difference in the way society hears them.
