Sound Fundamentals: Did you know that when you hear a sound, your brain instantly decodes two crucial characteristics to aid in your understanding of it: Pitch and frequency — Is the sound high, like a scream, or low, like a bass?

Is the sound loud like a hoover cleaner or quiet like a whisper?

Vibrations that move like waves through the air are what create sounds. When air particles vibrate, the particles nearby also vibrate. As the vibrations move away from the sound source, their intensity decreases. Tiny bones in your ear register the vibrations when the music reaches you; the rest is handled by your brain. Continue reading to learn more about these ideas, or continue reading to learn how sound can put your baby to sleep.

Frequency

Sound waves vibrate at a certain frequency. One vibration, or one cycle per second, equals one Hz, the unit of frequency measurement. While canines can hear sounds up to 45000 Hz, the human ear can only detect sounds between 20 and 20000 Hz.

Pitch explains how people feel Frequency (high pitch sounds are high frequency, low pitch are low frequency).
Amplitude

Sound waves’ amplitude can be thought of as their strength or power. Decibels serve to quantify amplitude (dB). A loud concert can reach 120 dB, whereas normal voices hover around 60 dB; anything over 85 dB is regarded as an undesirable level in the workplace; and 160 dB instantly perforates an eardrum.

Amplitude is described by intensity as it moves in a specific area, at a specific time, and in a specific direction.

Decibels

The measurement of sound intensity in decibels does not follow a straight line. This indicates that they do not increase linearly and are instead scaled on a logarithmic scale with a base of 10. This is because you actually need to multiply the intensity of a sound by about 10 to make it twice as loud. The logarithmic scale of decibels is more in line with how humans experience sound.

Hence, a power of 10 increase in intensity results from a 10 dB rise in amplitude. As comparison to the difference in volume between 60 and 120 dB, the difference in volume between 20 and 60 dB is negligible. Vacuum cleaner noise is 80 dB, average conversation is 60 dB, whispering is roughly 20 dB, and a jet taking off is 140 dB.

Octaves

The term «octave» refers to a frequency doubling. An octave, for instance, might be thought of as the range of frequencies between 20 Hz and 40 Hz or 100 Hz and 200 Hz.

The strange thing is that we don’t interpret the difference between 20 and 40 Hz and 10,000 and 20,000 Hz as being linear. Yet, higher frequency noises are more perceptible to human hearing, which helps to explain how we feel when we hear them, such as wailing babies.

White Noise

The waveforms of the noises you hear every day are often quite brief and have fairly random amplitude and frequency distributions. When low, mid, and high frequency noises are played concurrently and with the same strength, white noise results.

All the frequencies a human ear can hear (about 20 Hz to 20 kHz), randomly broadcast at the same amplitude, are what is known as white noise. It is sometimes compared to TV or radio static. White noise is a sound wave that is made up of all the frequencies that we can hear, blended together, in the same way that a beam of white light is made up of all the colours. Pink noise is frequently wrongly referred to as white noise.

White noise may not genuinely exist, despite what you may believe. White noise is made up of all audible frequencies at the same amplitude and might sound unpleasant to individuals since the human ear is more sensitive to higher frequencies.

Sounds in Colors

Similar to how distinct colours of light are defined by their frequency and amplitude, different «colours» of sound are as well.

Other colours have more or less power in the higher or lower frequencies than white noise, which has all audible frequencies present at the same amplitude.

Pink Noise

Compared to white noise, pink noise is less «bright» sounding. All of the audible frequencies are present in pink noise as well, but the intensity of the sound is much more evenly distributed since as the frequency doubles, it decreases in intensity.

More low-frequency tones and fewer high-frequency tones are used to create pink noise. White noise is less unbalanced than it.

Due to its equal power per octave, pink noise is frequently seen as being more flat and balanced.

Brown Noise

Brownian motion, a phenomenon that describes the random movements of particles, is the source of the name «brown noise,» not after the colour but rather after Robert Brown. Red is the «colour» of sound that brown(ian) noise most resembles. Pink noise and red noise are comparable, but red noise has even higher low-frequency intensities.

Even more low frequency tones are present in brown noise than in pink noise (sometimes called red noise). Beyond pink noise in depth

Energy decreases by around 1-3 dB each octave in pink noise and by about 6 dB per octave in red noise. Red noise is frequently heard as a deeper, roaring or rumbling sound by people.

Natural Noises

White noise is frequently connected to radio or television static, pink noise to rain or wind, and brown or red noise to thunder or a far-off waterfall. All of these sounds can be produced artificially by audio engineers, but they can also be found naturally in our surroundings.

Depending on how much emphasis is placed on high and low frequencies, sound can take many different forms, including rain, wind, waves, thunder, and noises from manufactured objects like tvs, vacuums, fans, and many others. When capturing natural sounds, the engineer must make sure that they cover as much of the entire frequency range as possible. Only then can the intensities of the sounds be changed to produce a variety of different tones.

Rest of the Rainbow

The most well-known colour of sound is white noise, which is played at the same volume for all frequencies.

Lower frequencies are prioritised in pink and red/brown noise.
Higher frequencies are prioritised in blue and violet noise.
The high frequency equivalent of pink is blue.
The high frequency counterpart of red and brown is violet.
The emphasis in grey noise alternates between low and high frequencies. It is strongest at the top and bottom of the frequency range, becoming weaker in the middle. Grey noise is frequently mistaken for white noise by the human ear.
Silence, or «black noise,» is the absence of sound.
High frequency sounds’ colours are less frequently connected with sleep since the human ear is more sensitive to higher frequencies, but they can be helpful in masking other high frequency sounds.

Sound’s advantages

A cushion of sound or a blanket of noise are common metaphors for white, pink, and crimson noise. Its advantages mostly come from their capacity to surround you and your infant with constant noise, drowning out any background noise, and muffling any rapid shifts or irregularities in environmental noise. Because of this, many people choose to listen to a standard CPAP machine than their partner’s erratic snoring.

The main advantage of white, pink, and red noise is to cover up any other sounds that can be disruptive to sleep. Depending on their sensitivity, people could prefer pink to white or red to pink, but the idea is the same in all cases.

Regular Claims

On the Internet, white noise is the subject of numerous claims. It promotes better sleep for your infant. It supports adults’ ability to focus and pay attention. Your memory will benefit. It helps you unwind. It relieves migraines. It facilitates quick naps. Overnight sleep benefits from it. It benefits those who experience tinnitus. Either that, or it acts in the complete other way. Addiction is a possibility. The hearing of your child may be harmed. Your tinnitus will worsen as a result.

You can use a white noise machine to put your baby to sleep without any discomfort, so don’t worry. There is no such thing as a baby sound addiction, and creating a schedule for sleeping is beneficial. Sleep schedules will need to vary as your child grows because they are continuously evolving! Employing a white noise machine properly won’t harm your child’s hearing. Certain devices have the capacity to play noises at loud volumes; you should be aware of this and make sure that the volume is set suitably for the distance between the device and your child.

Over the past few decades, numerous research have examined the advantages of white noise. You can find links to several of these studies below, but you should be aware that they were all conducted on rather tiny subject populations.

Studies on the benefits of white noise and sleep have not been done in sufficient numbers to establish firm conclusions.

The effects of white (and other colour) noise on infant, child, or adult sleep have not yet been the subject of large-scale, reliable investigations.

Bottom Line

The best piece of advise we can offer is to explore many options until you find one that works for you and your infant. It’s extremely likely that sound will aid in your baby’s slumber. Throughout the most of its life, your unborn child was subjected to the continual noise your body made within the womb. Beyond that, your child should be assisted by anything that creates a routine for sleep in order to get ready for it and adjust to it.

Attempt artificial white, pink, or red noises. Consider using natural sounds such as streams, waves, rain, thunderstorms, forest sounds, fire, wind, and more. Try hearing sounds from appliances like washing machines, vacuums, and hair dryers. Try out some human noises, such as heartbeats, uterine sounds, humming, or shushing. Don’t forget to play soothing music like lullabies.

Keep experimenting until you find something that works for you and your child because every baby is unique and different noises will work for different kids at different periods.

References

Contributors to Neighbour Noise Annoyance
White noise enhances new-word learning in healthy adults
Altering brain dynamics with transcranial random noise stimulation
Harmonicity aids hearing in noise
The Immune System Can Hear Noise
Phase Noise of SAW Delay Line Magnetic Field Sensors