The presence of low-frequency sounds accompanies us in many aspects of daily life. The occurrence of any sound within 20 Hz has a negative impact on the auditory organ, so it is worthwhile to use a variety of ways to prevent it as much as possible. Although the use of solid furnishings can be extremely helpful, it is also necessary to keep in mind the characteristics of the human ear, which reacts to such sounds with great sensitivity. In order to practically counteract the arrival of sensitive low sounds to our ears, there is a need to use professional equipment that can absorb harmful emissions and directionally absorb them. The idea here is to provide greater protection for humans, and thus make it easier for them to perform activities in the vicinity of the occurrence of low voice frequencies.
Low frequencies in the household
In order to deal effectively with sounds of the lower limit of hearing (20-50 Hz), it is necessary, first of all, to be aware of where they come from and what can cause them. These sounds are usually caused directly by humans and can take a wide variety of forms. Most often they manifest themselves in the form of walking noises, which are caused by stepping, stomping or moving certain objects. They can be heard most acutely on modern laminate floors – on such surfaces they spread with great ease. They spread much worse with leather carpets or wooden parquet floors, causing less damage to human ears. Do not forget that the degree of sound intensity is also affected by the degree of interior furnishings and the volume of the place of residence (e.g., a block of apartments, a house).
We can also encounter low-frequency sounds when using smartphones on a daily basis. This is because they emit all sorts of vibration sounds (e.g. calls, notifications, messages), with which it is impossible not to come into close contact when using this type of device. Many modern smartphones have extensive mono or stereo speakers, the regular operation of which at high volume can affect hearing significantly. However, we are not completely helpless in such a situation, as there is special software aimed at editing and correcting harmful bass. These programs reduce the occurrence of low-frequency sounds, which also brings considerable benefits when listening to music. This solution is able to largely preserve the good condition of hearing, making multimedia entertainment more pleasant.
It is worth remembering that, in addition to cell phones, there are quite a number of other useful devices in which the emission of low frequencies is the order of the day. These are devices, operating on the basis of electric motors, which we can encounter while staying in houses or apartments of contemporary trend construction. As a rule, these buildings are equipped with innovative fans or professional air-conditioning systems, whose fruitful work comes into contact with the sensitivity of our ears, causing a well-known noise. Its regularity makes not only the organ of hearing, but also human well-being suffer. This, however, does not entail – we can prevent it by using ear stoppers or putting on professional headsets.
Professional methods of preventing low sounds
1. use of bass traps, or bass traps (wideband)
The practical use of bass traps proves to be extremely beneficial when arranging or designing a room. This is because bass traps show great effectiveness when dealing with multiple sound bands – they often reduce emissions from 50 to 4000 Hz. The action of bass traps includes absorbing harmful low-frequency noises, the propagation of which can be heard as buzzing or rumbling. In order to use them, they should be placed in corner areas of rooms. Their proper placement will ensure partial elimination of low tones, since it is impossible to suppress all such noises. Bass traps are characterized by lightweight construction and attractive form – they are most often constructed of acoustic foam, glass fiber and mineral wool. Before using them, it is advisable to conduct a professional study of the sound capabilities of the room with the participation of an acoustician. Although bass traps are characterized by high efficiency, when it comes to suppressing sounds below 70 Hz, they look quite average.
2 The use of broadband absorbers
Usually they are in the form of wall or ceiling panels, used in the furnishing of commercial interiors. Their selection and practicality of use depends on the type of room, the degree of its furnishings, as well as the spatial size of the area. They are best suited for professional music studios, where the emission of low tones takes place relatively often. With the participation of broadband absorbers, it is possible to perform clean musical playing or vocals without any problems, as well as to receive the other person’s speech correctly and clearly without any interference. The success of these products lies in high-quality materials with acoustic properties. The construction of the best of them must not lack solid furniture board (HDF), nor multifunctional Isover wool.
3. use of tuned membrane traps
They allow you to combat a certain value of frequency that occurs within a given location. They are subject to configuration based on the nature of the room, and require the correct choice of mass and membrane. To do this, you need to use a professional calculator to calculate the volume of the traps, the determinant of which is the dimensions of the room of interest. When making calculations, you also need to specify (in the form of coordinates) the location of the listening point and sound sources. To adjust them for optimal functionality, it is good to perform a series of experiments and specialized measurements. They consist of sound-absorbing foams of varying density, and in practice are perforated – holes are made in them to facilitate acoustic penetration.
4 Use of Helmholtz resonators
This solution seems to be more effective than using membrane traps. These resonators – like the aforementioned traps – can be effectively tuned for given frequencies. They take the form of various blocks or housings, having holes cut in the shape of circles or squares. Wood is becoming a popular manufacturing material, and they can also consist of glass, as well as metal. An example of the use of Helmholtz resonator technology is the principle of acoustic diffusers, whose main purpose is to disperse the emission of sound waves as much as possible. These wooden forms satisfactorily reduce reverberation, eliminate fluttering echoes and improve the feeling of acoustic freedom in a room. We can find them in philharmonic halls (they are large openings in the walls there) or use them on their own, using them as an integral part of a home theater.