pupils of the 9th grade of the MKOU "Babezhskaya secondary school" Ksenia Stupnikova, Yana Gerasimova, head: Tetenkina Ekaterina Vladimirovna
This presentation is intended for a lesson on the topic "Sound, sound waves" for grade 9. Contains useful, interesting material. A large number of beautiful illustrations will make the lesson fun.
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Sound waves were performed by: 9th grade students of the MKOU "Babezhskaya secondary school" Stupnikova Ksenia, Gerasimova Yana supervisor: teacher of physics Tetenkina Ekaterina Vladimirovna
Sound is transmitted using sound waves. They spread from the sound source like circles of water from a thrown stone.
SOUND WAVES - mechanical vibrations, the frequencies of which lie within the limits of sound frequencies. Sound propagates in all elastic bodies - solid, liquid and gaseous, but cannot propagate in airless space.
Propagation of sound in solids. Sound travels best in solids. 4500m/s. So, putting your ear to the ground, you can hear what is happening far away from you. Propagation of sound in gases. Sound waves can travel through gases. The speed of sound in air is 340 meters per second. Propagation of sound in liquids. Sound waves in liquids always travel better than in gases (4 times faster). Propagation of sound in media
Any source of sound vibrates. Mechanical vibrations, whose frequency is more than 20,000 Hz, are called ultrasounds, and vibrations with frequencies less than 20 Hz are called infrasounds. The human ear does not hear ultra- and infrasounds, BUT ...
These sounds are good helpers for both humans and animals.
Bats emit high-frequency squeaks-signals and perceive their echo, that is, the reflection of these signals from various objects. The shorter the time interval between such a squeak and the echo from it, the closer the mice are to their target. Using sound to detect something is called echolocation.
Bats can distinguish the highest sound vibrations in the entire animal kingdom - up to 210,000 Hz.
Whales and dolphins also use the principle of echolocation to find their way into the sea. Perceiving the echo of sounds, they learn what objects and creatures are around them.
Not all animals hear sounds the way humans do. So, grasshoppers hear with their paws, making quick vibrations with them, they find out where the sound comes from. Snakes do not have ears and cannot perceive sounds through the air. But they pick up sounds by listening to the ground. Pisces hear with their whole body.
Ultrasound is used to examine materials. For example, to inspect an aircraft. By examining echo data, engineers can determine if there are any cracks or breaks in the thickness of the metal.
Earthquakes and explosions cause powerful vibrations in the soil. Such vibrations are called seismic waves. These waves travel through various fluids and rocks at different speeds. By measuring their speed, geologists can find out what is going on in the bowels of the Earth. Seismic waves also help find oil deposits.
Interesting Facts
If you hit a glass glass lightly, you can hear the sound of glass vibrating at its own frequency. The glass may break if this note is sung loudly next to it. Only a sound that matches the natural frequency of the glass can create a strong enough vibration for this to happen. How glasses break
Every body has its own frequency. In 1940, the Teikoma Bridge in the USA collapsed. This happened because the wind forced it to vibrate at its own frequency, which caused huge destructive vibrations. When crossing a bridge, soldiers never march in step, as this can cause the bridge to vibrate at a natural frequency. Destruction of bridges.
You can play the piano without even touching its keys. You need to open the piano lid, press the pedal and sing a note. When you finish singing, you can hear the same note from the piano. The vibrations of the voice cause the strings of the instrument to vibrate. Synchronous vibrations
In Chinese and Japanese pharmacies, you can now find music discs with very original names: "digestion", "migraine", "liver", etc. The Chinese use music instead of pills. And although the release of such music albums was mastered in the East, the healing properties of music were known back in Ancient Egypt It's just that this knowledge has been lost over time. Doctors have studied this phenomenon and proved that certain melodies have a beneficial effect on the human body. In the US, music therapy has become one of the most popular treatments. They will help you - with sleep disorders: "Sad Waltz" by Sibelius, "Melody" by Gluck, plays by Tchaikovsky. For a headache: Liszt's Hungarian Rhapsody, Beethoven's Fidelio. Relieve stress and calm down: Brahms' Lullaby, Schubert's Ave Maria, Chopin's mazurkas and preludes, Beethoven's Moonlight Sonata. From hypertension, Bach's Violin Concerto in D Minor. Today, the most famous women in the world use this method of therapy.
AT different countries In the world, there are entire associations that popularize and practice healing with the help of musical vibrations. Many publications and periodicals are devoted to this topic. In our country, music therapy has been practiced for a long time, but not too widely. However, you can use music therapy on your own, at home. The main thing is the presence of desire and self-confidence!
Sound
wavesMOU Sukhovskaya secondary school
Physics teacher -
Puchkova Svetlana Alexandrovna
The purpose of the lesson is to show the connection between physics and biology, to expand the concept of "sound waves", to talk about sounds in nature.
Lesson progressIntroduction
Sound waves: human audible, infrasound, ultrasound, hypersound
Acoustic signals
Acoustic properties of different habitats
Application of ultrasound
Anchoring
Echo - unchanging response
nature to questions that
we ask her Echo - the same answer
nature to questions that
we ask her
Usually, when talking about the sounds made by animals, they first of all talk about birds, since most often we hear their voices. As for other living organisms, many consider them almost dumb. Although in reality this is not the case, we just cannot always hear them, the sound connection between them is carried out at a height inaccessible to our hearing.
Why do we
ears given by nature?
Are all sounds
can we hear?
About sounds...
In air, the speed of sound was first measured in 1836 by the Frenchman M. Marsenne. At a temperature of 200 C, it was 343 m / s. In air, the speed of sound was first measured in 1836 by the Frenchman M. Marsenne. At a temperature of 200 C, it was 343 m/s.
The speed of a bullet from a Kalashnikov assault rifle is 825 m / s, i.e. the bullet outruns the sound of the shot and reaches the victim before the sound arrives.
Information:
Acoustics (from the Greek akusticos - "auditory") - the study of sounds. Acoustics (from the Greek akusticos - "auditory") - the study of sounds.
There are "audible" and "inaudible" sounds.
In the ordinary sense, sound is what the human ear perceives.
Sounds are heard not only by people, but also by animals, and even plants react to sounds to one degree or another.
Currently
sound can be divided
by frequency for the following
four
main range
Slide #10
sound,
audible
human ultrasound
hypersound
infrasound
109 < <1013 Гц
16< < 20 000 Гц
Slide #11
Well perceived by fish, cats and whales. Well perceived by fish, cats and whales.
infrasound
Slide #12
Whales have very fine hearing and are able to pick up a wide range of sound waves. Whales have very fine hearing and are able to pick up a wide range of sound waves.
Echolocation allows the whale to determine how large an object is, how far it is, and in what direction it is moving.
Slide #13
The manul that lives in the steppe and the velvet cat that lives in vast open spaces should hear their prey from afar. The manul that lives in the steppe and the velvet cat that lives in vast open spaces should hear their prey from afar.
Therefore, in these two breeds of cats, the ears are widely spaced and arranged in such a way that they work like a good antenna: they pick up the weakest sounds, amplify them and transmit them to the eardrum.
Slide #14
The Japanese keep this fish in home aquariums, which can predict natural disasters in a few hours. The Japanese keep this fish in home aquariums, which can predict natural disasters in a few hours.
gambusia
Fish react an hour before an earthquake. If the earthquake is not very strong, they gather in a dense flock, their bodies are pressed against each other and stand with their noses to the epicenter, literally pointing at it. And when the earthquake is strong, the fish jump out of the aquarium.
Slide #15
Bats, dolphins, dogs perceive well. Bats, dolphins, dogs perceive well.
Ultrasound
Student Message
Slide #16
Bats can perceive the echo from their signal at a pressure 10,000 times less than the emitted signals. Bats can perceive the echo from their signal at a pressure 10,000 times less than the emitted signals.
The bats
when probing
spaces emit and
receive impulses
frequency from 30 to 150 kHz.
At a distance of 5-10 cm from the head of the animal
ultrasonic pressure reaches 60 mbar
(1 bar=100 kPa).
Volatile
mouse
Slide #17
The place of origin of sounds is the larynx, in which a zone of high pressure is created before the “ejection” of the signal
Bats rely on their acoustic memory.
During familiarization flights, when traditional ultrasonic location is used, the animals memorize the “sound picture” of space.
Slide #18
To obtain information about the presence of fish or objects, the bottlenose dolphin (a type of dolphin) emits a series of short signals perceived by humans as clicks.
Hearing limits
perception in dolphins
stretch
75 to 180 kHz Dolphins
Slide #19
Dolphins make over 700 ultrasonic clicking sounds per second.
returns
through a certain
time interval
in the form of an echo and prompts
dolphin distance
to the nearest
school of fish.
Slide #20
There are approximately 1018 different insects on earth. All of them differ in the number of flaps of their wings, which means that the wavelength that they generate is different. In fish, organs are predominantly used, the main function of which is not directly related to the generation of sounds (these are fins, swim bladder). Acoustic signals
Slide #21
mosquitoes make around mosquitoes make around
1000 wing beats
per second
bumblebees - about 200
butterflies - 5-10 strokes per second
bees flying light - 400-500
strokes per second
bees with a burden - about 200 times per second
Slide #22
Studies have shown that if you talk to a plant, they grow better. Research has shown that if you talk to a plant, they grow better.
The sound waves of our voice make plant cells vibrate.
Plants affected by classical music and jazz grow dense, healthy leaves and well-developed roots.
Under the influence of rock, their roots develop so poorly that the plants begin to die.
Plants
Slide #23
Why are they buzzing? Why are they buzzing?
Hummingbirds flap their wings so fast that they generate a high-pitched buzzing sound.
Slide #24
The habitat of animals influences the formation of the features of the sound signaling system in them
Acoustic properties
different habitats
Slide #25
In the desert and steppe, the air during the day is characterized by low humidity and high temperature. Under such conditions, the transmission of sounds with a frequency of more than
1 kHz, since these frequencies are strongly absorbed.
At a relative humidity of 20%, the attenuation of the sound with a frequency of 3 kHz is 14 dB at 100 m.
Slide #26
The propagation of sound in a forest or thick grass is affected by the density and height of the vegetation cover.
So, when sound with a frequency of 10 kHz passes over dense tall grass, the attenuation is 0.6 dB per 1 meter, while when it propagates over the ground with sparse low grass, it is only 0.18 dB per 1 meter. On the propagation of sound in a forest or in dense grass, the density and height of the vegetation cover is affected.
So, when a sound with a frequency of 10 kHz passes over dense tall grass, the attenuation is 0.6 dB per 1 meter, while when it propagates over the ground with sparse low grass, it is only 0.18 dB per 1 meter.
Slide #27
EarthquakesEarthquakes
Tsunami
Animals predict:
Message
student
Slide #28
People simply do not notice some of the phenomena that precede an earthquake, but animals that are closer to nature can feel them and show concern. Horses neigh and run, dogs howl, and fish start jumping out of the water. Animals that normally hide in burrows, such as snakes and rats, suddenly come out of their burrows: chimpanzees in zoos become restless and spend more time on the ground. People simply do not notice some of the phenomena that precede an earthquake, but animals that are closer to nature can feel them and show concern. Horses neigh and run, dogs howl, and fish start jumping out of the water. Animals that normally hide in burrows, such as snakes and rats, suddenly come out of their burrows: chimpanzees in zoos become restless and spend more time on the ground.
Slide #29
There was a very famous case in Leninakan: two hours before the earthquake, a dog - Laika - pulled its owner out of the house onto the street, although he had recently returned from a walk. When the owner of the husky called the police, he was ridiculed. I called the city executive committee - the same reaction. He ordered all the neighbors to leave the house and took his family out. Those people escaped, but tens of thousands died. There was a very famous incident in Leninakan: two hours before the earthquake, a dog - a husky - pulled its owner out of the house onto the street, although he had recently returned from a walk. When the owner of the husky called the police, he was ridiculed. I called the city executive committee - the same reaction. He ordered all the neighbors to leave the house and took his family out. Those people were saved, and tens of thousands died
Slide #30
I live in Irkutsk. This is a seismic zone. In 1998, my cat behaved very strangely before the earthquake. Hiding under the bed, meowing loudly, running after everyone like a tail. I was afraid… Soon aftershocks started. I live in Irkutsk. This is a seismic zone. In 1998, my cat behaved very strangely before the earthquake. Hiding under the bed, meowing loudly, running after everyone like a tail. I was afraid ... Soon aftershocks began.
Slide #31
If earthquakes happen under the ocean, then they can form a giant wave with a height of more than 30 m.
Such a wave is called a tsunami.
Slide #32
Tsunamis are giant waves.
Once in shallow water, they slow down their run, but their height increases dramatically.
Slide #33
EcholocationEcholocation
Ultrasonic flaw detection
ultrasound
Application
ultrasound
Slide #34
Echo is also used in ultrasound scanning to look inside the human body. Bones, muscles, and fat reflect sound waves in different ways. The computer uses this information and creates an image of the desired organ.
Description of the presentation on individual slides:
1 slide
Description of the slide:
Sound waves Completed by: Ruban Anastasia Gabova Valeria, students of grade 11A checked by: Glushkova T.A. Physics teacher
2 slide
Description of the slide:
Sound Like any wave, sound is characterized by amplitude and frequency spectrum. An ordinary person is able to hear sound vibrations in the frequency range from 16-20 Hz to 15-20 kHz. Sound below the human hearing range is called infrasound; higher: up to 1 GHz - by ultrasound, from 1 GHz - by hypersound. The loudness of a sound depends in a complex way on the effective sound pressure, frequency and form of vibrations, and the pitch of a sound depends not only on the frequency, but also on the magnitude of the sound pressure. Sound is a physical phenomenon, which is the propagation of mechanical vibrations in the form of elastic waves in a solid, liquid or gaseous medium. In a narrow sense, sound refers to these vibrations, considered in connection with how they are perceived by the sense organs of animals and humans.
3 slide
Description of the slide:
Sound waves in gases and liquids can only be longitudinal, since these media are elastic only with respect to compressive (tensile) deformations. In solids, sound waves can be both longitudinal and transverse, since solids are elastic with respect to compressive (tensile) and shear deformations. Sound in gases Sound in liquids
4 slide
Description of the slide:
Sound Intensity Sound intensity (or sound strength) is a value determined by the time-average energy carried by a sound wave per unit time through a unit area perpendicular to the direction of wave propagation: The sensitivity of the human ear is different for different frequencies. In order to cause a sound sensation, the wave must have a certain minimum intensity, but if this intensity exceeds a certain limit, then the sound is not heard and only causes pain. Thus, for each oscillation frequency, there is the smallest (threshold of hearing) and the largest (threshold of pain) sound intensity that can cause sound perception. I=W/(St)
5 slide
Description of the slide:
6 slide
Description of the slide:
The level of sound intensity Many thousands of teenagers pay for the passion for loud music, especially fashionable in our time, with acquired hearing loss. Sound Threshold of hearing vdb Barely audible sound 0 Whisper near the ear 25-30 Speech of medium volume 60-70 Very loud speech (shout) 90 Roar of an airliner taking off 120 At rock and pop music concerts in the center of the hall 106-108 At rock and pop music concerts at scenes 120
7 slide
Description of the slide:
Impact of sound waves The Swiss scientist Hans Jenny studied the effect of sound on inorganic matter, including water. Under the influence of sound, a drop of water, vibrating, took the form of a three-dimensional star or a double tetrahedron in circles. The higher the frequency of vibration, the more complex the forms were. But as soon as the sound subsided, the most beautiful formations again became in the form of a drop of water.
8 slide
Description of the slide:
Japanese scientist Professor Emoto Masaru conducted experiments on the effects of various music, prayers, obscene expressions, positive and negative statements on water. The experiments of Emoto Masaru showed that the result of the impact of spiritual and classical music, prayers and words that carry positive energy is the formation of amazingly beautiful snowflakes in ordinary water.
9 slide
Description of the slide:
10 slide
Description of the slide:
On the contrary, when exposed to obscene expressions, words that carry negative energy, in ordinary water, the crystalline structure did not form at all, and the previously well-formed crystalline structure of water was destroyed. The structure of water copies the energy-informational field in which it is located, and we are 90% water. The positive or negative energy of the sounds of a speech or a piece of music affects the entire body as a whole, down to the structure of the cells.
11 slide
Description of the slide:
Russian scientists led by P.P. Garyaeva with the staff of the Institute of General Genetics proved that DNA perceives human speech. If a person uses obscene expressions in his speech, his chromosomes begin to change their structure, a kind of negative program begins to be developed in DNA molecules, which can be called a “self-destruction program”, and this is transmitted to the descendants of a person. Scientists have recorded: a swear word causes a mutagenic effect, similar to radiation with a power of a thousand roentgens!
12 slide
Description of the slide:
On the contrary, high-frequency sounds in a human-friendly range have a beneficial effect on us, increasing energy levels, causing joy and good mood. High-frequency sounds activate brain activity, improve memory, stimulate thinking processes, at the same time relieving muscle tension and balancing your body in various ways. After researching music written by various composers, French otolaryngologist Alfred Tomatis found that Mozart's music contains the most high-frequency sounds that recharge and activate the brain. It is very useful to listen to the voices of birds, the sounds of nature. An extended speech range (from 60 to 6000 Hz) is also important, because speech is a complex signal, which, in addition to the fundamental tones, contains many harmonics that are multiples of them in frequency. Our native Russian language is very promising in this sense, because it includes both very low and very high frequencies. The area of American and English is much narrower.
13 slide
Description of the slide:
Applications of sound waves Ultrasonic waves have found more applications in many areas of human activity: in industry, in medicine, in everyday life, ultrasound was used for drilling oil wells, etc. Until now, high-frequency sound waves have been used in medicine only for diagnosing the condition of internal organs. Now they are becoming a precision instrument of the surgeon. With their help, it is possible to "weld" destroy tumors without anesthesia, without a single incision of living tissues.
Sound waves. Sound speed
Sound is mechanical waves perceived by the human ear that cause sound sensations.
Sound sources can be any bodies that oscillate with sound frequency (from 16 to 20,000 Hz).
range of audible sounds.
Children
16-22000
Man in his 20s
Man aged 35
16-20000
Man aged 50
16-15000
16-12000
Cricket
Grasshopper
10-100000
Frog
50-30000
Dolphin
400-200000
A person does not perceive infrasound, although he can feel its effect due to resonance.
The frequency of infrasound oscillations is less than 16 per second, that is, below the threshold of hearing.
The concept of ultrasound
Ultrasound- high-frequency mechanical vibrations of particles of a solid, liquid or gaseous medium, inaudible to the human ear. The frequency of ultrasound oscillations is above 20,000 per second, i.e., above the threshold of hearing.
Ultrasound and infrasound
Ultrasound and infrasound are as widespread in nature as the sound waves. They are emitted and used for their "negotiations" by dolphins, bats and some other creatures.
Sound sources
natural
artificial
(tuning fork, string, bell, membrane, etc.)
For sound to exist :
1. Sound source
2. Wednesday
3. Hearing aid
4. Frequency 16–20000 Hz
5. Intensity
Sound wave receivers:
Natural – ear. Its sensitivity depends on the frequency of the sound wave: the lower the frequency of the wave, the lower the sensitivity of the ear. Exceptional selectivity: the conductor captures the sounds of individual instruments.
Artificial – microphone. It converts mechanical sound vibrations into electrical ones.
sound propagation
Sound propagates in any elastic medium - solid, liquid and gaseous, but cannot propagate in space where there is no substance (for example, in a vacuum)
From the history of the discovery of the speed of sound .
The speed of sound in air was first determined in 1708 by the English scientist William Derem. Cannons were fired at two points, the distance between which was known. At both points, the time intervals between the appearance of fire upon firing and the moment when the sound of a shot was heard were measured. Speed of sound in air 340 m/s
Pitch, tone and volume
part 2
Physical characteristics of sound
Objective:
Sound pressure (pressure exerted by a sound wave on an obstacle in front of it);
The spectrum of sound is the decomposition of a complex sound wave into its component frequencies;
Sound wave intensity.
Subjective:
- Volume
- Height
- Timbre
Pitch - characteristic, which is determined by the frequency of oscillations . The higher the frequency of the body that produces vibrations, the higher the sound will be.
Timbre called sound color .
Timbre is the difference between two identical sounds played by different musical instruments.
Volume sound depends on the amplitude of oscillations .
Sound volume
The loudness of the sound depends on the amplitude of the oscillations: the larger the amplitude of the oscillations, the louder the sound.
Loudness is the subjective quality of the auditory sensation that ranks sounds on a scale from quiet to loud.
The unit of sound volume is called sleep.
Timbre.
The quality of musical sound, its peculiar “coloring” is characterized by timbre. Here are some characteristics of the timbre: thick, deep, masculine, harsh, velvety, matte, shiny, light, heavy, rich.
The timbre depends on the material from which the instrument is made, on the shape of the instrument.
pure tone
A pure tone is the sound of a source that makes harmonic oscillations of one frequency.
The branches of the tuning fork perform harmonic (sinusoidal) oscillations. Such oscillations have only one strictly defined frequency. Harmonic oscillations are the simplest type of oscillation. The sound of a tuning fork is pure tone .
Noise - These are loud sounds of different frequencies, merged into a discordant sound.
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and happiness
smile at you!
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Text content of presentation slides: Sound wavesSpeed of sound We are surrounded by the world of sounds: musical instruments voices of people traffic noise sounds of birds and animals What is sound? Sound is elastic longitudinal waves that cause auditory sensations in a person. Sound sources are physical bodies that vibrate, i.e. tremble or vibrate at a frequency of 20 to 20,000 times per second. There are both natural and artificial sources of sound. One of the artificial sound sources is the tuning fork. ●The pitch of the sound depends on the vibration frequency. The frequency is measured in Hz (Hertz) ● Loudness depends on the amplitude of oscillations in the sound wave. Sleep is taken as a unit of sound volume. Sound volume is 1B (1 Bel) In practice, loudness is measured in decibels (dB). 1 dB = 0.1B. How will the volume of a sound change if the amplitude of the oscillations of its source is reduced? Sound volume will decrease Does sound propagate in all environments? In water. In the air. in solids. There is no sound in a vacuum! Conclusion: Sound propagates in any elastic medium - solid, liquid and gaseous, but cannot propagate in space where there is no substance. New material. Sound waves are the waves perceived by the human ear. The audio frequency range is approximately 20 Hz to 20 kHz. In what range can the human ear perceive elastic waves? The human ear is able to perceive elastic waves with a frequency of approximately 20 Hz to 20 kHz. Animals perceive waves of other frequencies as sound. What is the speed of sound? It is known that during a thunderstorm we first see a flash of lightning and only after a while hear thunder. This delay occurs due to the fact that the speed of sound in air is much less than the speed of light coming from lightning. The speed of sound in air: The speed of sound in air was first measured in 1636 by the French scientist M. Mersenne. At a temperature of 20°C, it is equal to 343 m/s, i.e. 1235 km / h. The speed of sound depends on the temperature of the environment: with an increase in air temperature, it increases, and with a decrease, it decreases. At 0°C, the speed of sound in air is 331 m/s. Sound travels at different speeds in different gases. The larger the mass of gas molecules, the lower the speed of sound in it. So, at a temperature of 0 ° C, the speed of sound in hydrogen is 1284 m/s, in helium - 965 m/s, and in oxygen - 316 m/s. In warm air, the speed of sound is greater than in cold air, which leads to a change in the direction of sound propagation. What is the speed of sound in water? The speed of sound in water was measured in 1826. J. Colladon and J. Sturm. The experiment was carried out on Lake Geneva in Switzerland. On one boat they set fire to gunpowder and at the same time struck a bell lowered into the water. The sound of this bell, with the help of a special horn, also lowered into the water, was caught on another boat, which was located at a distance of 14 km from the first. The speed of sound in water was determined from the time interval between the flash of light and the arrival of the sound signal. At a temperature of 8 °C, it is approximately equal to 1440 m/s. Different speeds of sound of different substances: (table in the textbook, p. 130) Substance Speed of sound, m/s Air (at) 343.1 Hydrogen 1284 Water 1483 (at) Iron 5850 Sea water 1530 Rubber 1800 Formulas for finding the speed of sound. – speed (m/s) -wavelength (m)ⱴ- frequency (Hz)S-distance (m) t-time (s) T-period (s) The human ear is a very sensitive device. With age due to loss of elasticity tympanic membrane people's hearing deteriorates. Useful information Causes of hearing loss: Work near powerful aircraft, noisy factory floors. Frequent visits to discos and excessive passion for audio players. The noisiest city in the world is Tokyo. Noise pollution is one of the urgent problems today. Industrial enterprises, airfields are being built on the outskirts of the city, and noise suppression devices are also used.