Human speech is transmitted by sound waves (hearing sound). In general, we may like it better when someone speaks pleasantly than when they scream. Bach's music may be more harmonious for someone than heavy metal, although tastes vary. This brief overview roughly explains:
- around the normal hearing range, which runs from 20 to 20,000 Hertz
- around low-frequency sound ranges from 20-90 Hertz
- about infrasound, which occurs in the range of 0-20 Hertz
- about ultrasound, this range starts at 20,000 hearts.
Sound waves are measured in length in Hertz (Hz), where 1 Hertz corresponds to one vibration per second. The volume is measured in decibels (db). In the normal sound wave range, the main problem is noise, while in the infrasound range it is more about the feeling of pressure and body vibration. Ultrasound involves very high-pitched sounds that are barely audible, but can still have an impact on people's well-being. Ultrasound and infrasound are inaudible noise in the range above and below the frequency ranges perceptible to the human ear. In childhood, the ear can hear up to 20,000 Hertz, in middle age people can hear sounds between 60 and 15,000 Hertz and in old age around 60 this range is 100 to 10,000 Hertz. For example, a bat can hear up to 380,000 hertz, a whale up to 150,000 hertz. Sound and noise are not only heard with the ears, but also received by the body and psyche. Every body, every organ, every cell, every muscle, nerve and bone reacts differently to sound and vibration and has different resonance capabilities. Noise is one of the biggest environmental problems of our time and also poses a high risk of heart attack.
As already mentioned, the loudness of sound is expressed in decibels (db). The lower the frequency in Hertz, the louder the sound level must be in dB. The human ear can perceive sounds at very low volumes in the range of 3000-4000 Hz, while the sound level in the infrasound range has to be very high in order to be heard at all. Sound waves travel through the air at 343 meters per second.
dB(A) - Beispiele
0 - Definierte Hörschwelle
10 - Blätterrauschen im Wald
20 - Tropfender Wasserhahn
30 - Flüstern
40 - Brummen eines Kühlschranks; leise Radiomusik
50 - Leise Radiomusik; übliche Tagespegel im Wohnbereich
60 - Umgangssprache; PKW in 15 m Abstand
70 - Staubsauger
80 - PKW mit 50 km/h 1 m Abstand; max. Sprechlautstärke
90 - LKW-Motor 5 m Abstand; PKW mit 100 km/h in 1 m Abstand
100 - Kreissäge, Lärm in einem Kraftwerk; Posaunenorchester
110 - Propellerflugzeug 7m Abstand; Bohrmaschine; laute Diskothek
120 - Verkehrsflugzeug 7 m Abstand; Beginn der Schmerzgrenze
130 - Düsenjäger 7 m Abstand; Walkman Maximal, Schmerzgrenze
160 - Gewehrschuss in Mündungsnähe
Problem noise in the normal sound range of 20 to 20,000 Hertz
Noise pollution can be caused by the following causes, among others: Loud music or television noise from the neighbor, the neighbor's mowing machines, the neighbor's pets, car traffic, trams and trains, sports facilities, restaurants, beer gardens, industry and commerce, construction sites and aircraft noise. However, humming refrigerators, ventilation systems, air conditioning systems, heat pumps of heating systems can also become sources of interference, especially in the low-frequency sound range of 20-90 Hertz.
The noise limits on the subject of noise and sound are regulated in accordance with the statutory “TA Rausch” (technical instructions for protection against noise). Here is an excerpt for the noise limits:
Unfortunately, some sources of noise are partially excluded in “TA-Lärm”, such as road, rail and air traffic, sports, leisure and agricultural facilities, open-air restaurants and also construction sites. Traffic noise on roads and railways in residential areas must be kept to an average of 59 dB during the day and 49 dB at night, and 64 dB and 54 dB respectively in mixed areas. According to VDI guideline 2058, an average of a maximum of 55 dB is permitted in the office workplace for predominantly intellectual activities.
Problem of infrasound and low frequency sound waves
Cause: Motors in refrigerators or air conditioning systems, pumps for heating or aquariums, ventilation or machines, ventilation systems, compressors and pumps as well as neighbors walking around can cause floors to vibrate. Wind turbines. Transformers for low-voltage halogen lighting, subway and railway, modern heating systems with heat pumps including their fans, transformer houses, mobile phone transmitters, especially their electronics and ventilation, substation and transformation systems of the network operators as well as water pumps in the street.
Sound is called low-frequency if its predominant energy components are in the frequency range of less than 90 Hertz (Hz); 1-20 Hertz is then the range of infrasound. Low frequency sound waves have a long wavelength, a tone of 20 Hz has a wavelength of 17 meters, a tone of 50 Hz has a wavelength of 3.40 meters. Low-frequency sound waves can propagate over large distances almost unhindered and are generally difficult to shield. Low-frequency noise emissions often lead to complaints in the neighborhood if the standards of the legal “TA noise” criteria are adhered to. The perception and effect of low-frequency noises can differ significantly from the perception and effect of medium or high-frequency noises. In the frequency range below 20 hertz = infrasound there is no longer any pronounced hearing sensation, but a Hungarian researcher even received the Nobel Prize for discovering that the ear can hear down to 1 hertz. Stresses in the infrasound and low-frequency range are often perceived as pulsations and vibrations. Those affected feel pressure in their ears and often complain of feelings of insecurity and fear. A special effect of infrasound is a reduction in the breathing frequency. Particularly in the infrasound range, strong nuisance can cause windows and doors to shake or parts of buildings and objects to vibrate noticeably.
In the frequency range from 20 Hz to around 60 Hz, the noises are audible at the appropriate volume, but the perception of pitch is only very weak. Beats can often be perceived. Those affected complain of a buzzing or vibrational hum in the head or a feeling of pressure in the stomach, which is judged to be unbearable and which is only partially dependent on the volume and which leads to severe annoyance in the case of stationary noise emissions. Feelings of insecurity and fear, panic attacks, a reduced breathing rate, symptoms of fatigue and difficulty concentrating are also possible physical stresses.
In the frequency range from 60 Hz onwards, the transition to normal pitch and noise sensations takes place. The noises are particularly annoying when they contain sound. In living areas, low-frequency noises can cause considerable nuisance just when they are noticed, especially at night when other noise levels are low.
Measurements and evaluation of low-frequency noise emissions in the neighborhood are carried out in accordance with the legal DIN 45680 standard.
Impact of strong vibrations on people and bodies
Source: INDEKLIMA – LYD, Polyteknisk Forlag 1979
Table 10.3
Examples of the effects of strong vibrations on people with approximate frequency ranges (according to STEPHENS)
Vibrations can be transmitted to the body through direct contact with vibrating components. Parts of the body can also be caused to vibrate by powerful sound waves in the surrounding air, especially infrasound.
Effect
Frequency range in Hz
perception 01, - 10,000
Motion sickness 0.1 - 1
Influence on balance 0.1 - 10,000
Disturbance of breathing and speech 1 - 100
Reduced ability to work 1 - 1,000
Difficulty seeing 3 - 1,000
Resonance of body organs 4 - 100
Suffering caused by shocks 1 - 100
Damage due to hand tools 100 - 10,000
In buildings, vibrations in the range above 80 Hz have no practical significance. Below 80 Hz, vibrations can be roughly divided into two frequency ranges with different effects:
very low frequencies (approx. 0.1 – 1 Hz) and
a higher frequency range (approx. 1 – 80 Hz).
Below 1 Hz, the most significant effect of vibration is motion sickness, in which the symptoms are the same as for sea and motion sickness, i.e. nausea, paleness, cold sweat, general discomfort and possibly vomiting. In addition, dizziness and balance disorders may occur. There is no complete explanation for the development of motion sickness, but reference can be made to STEPHENS 3, chap. 11 for a more in-depth look at the topic.
At very low frequencies the whole body vibrates as a unit, but at frequencies above 1 to 4 Hz individual organs or parts of the body will vibrate particularly vigorously due to resonance, causing a long series of symptoms, as shown in the table below. The table is based on tests with very strong vibrations lasting 1 minute and 3 minutes. It is clear from the specified frequency ranges that at very low frequencies below around 10 Hz, the centrally located organs with relatively high mobility and low resonance frequencies are particularly influenced. Conversely, organs with relatively small mobility and higher resonant frequencies are placed peripherally, and they are influenced at higher frequencies
Table 10.4
The most clearly recognizable symptoms between 1 and 20 Hz when exposed to vertical vibrations on sitting people in the borderline range of harmful influences when exposed for at least 1 minute.
Symptom and frequency range
General discomfort 4 Hz
head and neck
Headache 13 - 20 Hz
Sensation of “lump around throat” 12 - 16 Hz
Lower jaw in resonance 6 - 8 Hz
Speech influenced by resonances in the larynx and trachea 13 - 20 Hz
chest
Breathing is affected 4 - 8 Hz
Shortness of breath 1 - 3 Hz
Chest pain 5 - 7 Hz
stomach region
Muscle contractions in the abdominal wall 4.5 - 9 Hz
Stomach pain 4.5 - 10 Hz
Pelvic region
Urgency 10 - 18 Hz
Urge to defecate 10.5 - 16 Hz
Skeleton and muscles
Muscle contractions in arms and legs 4.5 - 9 Hz
Increased muscle tension in legs, back and neck 8 - 12 Hz
Problem ultrasound from 20,000 Hertz (low 15,000)
With ultrasound, the noises are more likely to be perceived as hissing, whistling and beeping. In Great Britain, noise emitters are used to scare loitering young people away from certain places. The frequency of 17,000 Hertz is transmitted at a high volume of over 100 dB. You can actually speak of a psychotronic weapon here. Wild boar cannons can reach a volume of 130 dB and marten traps in carports don't just make life difficult for martens. I am aware of reports in which the authors assume that millions of tinnitus cases have to do with these marten traps in carports and cars. These ultrasonic devices are also available to repel mosquitoes, moles and birds. The martens' eardrums burst at the high volume and since they are then deaf, they come back and continue to gnaw on the car cables.
An important aspect when it comes to ultrasound are the power supplies in energy-saving lamps and screens as well as power supplies in halogen systems. They scream in the apartment at inaudible 20, 30, 40, 50 and 128 kilohertz.
You can only hear the high frequencies very faintly, or not at all, and yet they are still annoying and have an unconscious effect on people. In our opinion, the frequencies are just as bad as the marten traps because they are present in everyone's everyday life. But here too a partial remedy can be provided.
Ultrasound is also viewed critically by scientists and doctors. Strong ultrasound devices, so-called Dopplers, should not be used on pregnant women in the first few weeks. Various studies have indicated that the likelihood of losing the baby is greater with such diagnostic devices than with conventional standard treatments. Stunted growth and speech disorders are also mentioned.
What can you do yourself?
=> Check your apartment for loud noise sources, often these can be old refrigerators.
=> Avoid ultrasonic defense devices and protect your ear against tinnitus and of course the animals too.
=> If necessary, install new soundproof windows later.
=> Don't damage your ears with music that is too loud. Young people in particular should be careful with headphones, as this creates even stronger alternating magnetic fields.
=> Reduce medical ultrasound examinations to a minimum.
What we can do for you?
1.) With our Dr. With the Jordan Class 2 measuring device, we can carry out measurements from 5 to 20,000 Hertz in order to determine your basic sound exposure. This concerns the normal sound range of 90 - 20,000 Hertz, but also the infrasound range of 5-20 Hertz and the low-frequency sound range of 20-90 Hertz. Measurements by experts and appraisers cost several thousand euros, but we offer a relatively inexpensive preliminary measurement. If it then turns out that legal limits are being exceeded in the long term, an expert can still be called in in step 2
2.) Sometimes the situation requires long-term measurements to be carried out, here we offer 24-hour measurements, see also measurement setup. Of course, our measuring device is recalibrated before each use.
3.) With a bat detector, we can detect ultrasonic pollution in the range of 19 to 130 kilohertz in your apartment and give you tips for renovation.
4.) Measurements can be carried out in accordance with the legal framework of “TA-Lärm” or in accordance with DIN standard 45680 (for frequencies between 10 and 80 Hz). If the dB(C) values are more than 20 dB above the dB(A) sound levels, low-frequency sound exposure can be assumed.
Note: Sound waves are measured in hertz (Hz) or kilohertz, the volume in decibels (db).
Possible health effects
In the specialist literature we find the following information about symptoms and diseases that are associated with noise, infrasound and ultrasound: stomach and intestinal ulcers, heart and circulatory diseases, nervous disorders, sleep and concentration disorders, stress symptoms and high blood pressure, ringing in the ears and deafness, tinnitus , headaches and nausea, depression and behavioral problems, narrowing of blood vessels and digestive problems, sleep disorders and increased susceptibility to cancer. Constant release of stress hormones such as adrenaline, norepinephrine and cortisone, increased blood fat and blood pressure values. Permanent psychological and physical damage and disorders of the nervous system caused by noise have been scientifically confirmed.
