Loudness of Sound - Difference Between Loudness & Pitch

Edited By Vishal kumar | Updated on Jul 02, 2025 04:50 PM IST

In this article, the loudness of sounds, we discuss terms like pitch meaning, factors on which pitch depends, the loudness of sounds depends on, the pitch of the sound is determined by or loudness of sound is determined by and we also discuss what is rise and fall in pitch, high pitch meaning, the definition of loudness, same pitch, voice pitch, quality of sound depends on, etc.

Loudness of Sound - Difference Between Loudness & Pitch

Sounds are a sensation with which every living being is familiar. Sound is commonly produced by vibration like when we touch the string of a guitar string of the guitar vibrates and produces and we hear the pleasant sound of the guitar. Sound is a form of energy and is produced only when some material body is made to vibrate. Human being produces sound by his vocal chord. Put your fingers on your throat, then speak some words. You sense a vibration in your vocal chord, that vibration is the cause for the production of the sound.

It is transmitted through a material medium producing the sensation of hearing in our ears. A medium can be a matter or a substance, sound can propagate in solid and liquid at a greater speed than through the air.

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The medium required for propagation of sound must have the following properties:

A medium must be elastic.
A medium must have inertia.
The frictional resistance of the medium should be negligible.

It is important to note that sound travels in the form of waves known as sound waves. A sound wave is a longitudinal wave that means that sound travels in back and forth motion in the same direction in which waves travel. Air is compressed and expands due to sound waves.

As the air spreads through the air, the particles end up bunching together in some places and spread out into another. Together with all the bunching and the spreading out cause areas of high pressure and low pressure to move through the air that is why sound waves describe pressure as waves.

It is useful to describe sound waves as pressure waves because we can make devices that can detect the changes in pressure.

That is how some microphones work. They use a diaphragm stretched over a sealed compartment and as sound waves pass by they create areas of the low and high pitch in the compartment. The difference in pressure causes the diaphragm to move back and forth, which electronics then translate into audio data. Your eardrum works in the same way.

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Diaphragm

We hear different sounds in our daily life. We like music or the sounds of birds but no one likes the sound of horns of vehicles in traffic. What is the reason all these sounds are very much different from each other? Sound has some characteristics, which make all these sounds different from each other.

Loudness
Pitch
Quality

Let’ discuss these terms

Loudness: What is the loudness of the sound? Loudness can be defined to differentiate between two different sounds from the same source but on different levels. It means we can easily differentiate which sound is soft and which one is loud. The loudness of the sounds depends upon the following factors and the loudness of the sound is determined by these factors:
Amplitude
Distance from the source
The density of the medium
The surface area of the vibrating body
Amplitude: The maximum height above or below the sound waves from their mean position is known as amplitude. In fig, a sound wave shown PA, RB, QC, and SD are maximum displacements from their mean positions P, Q, R, and S respectively, so they represent amplitude.

The loudness of the sound depends upon its amplitude. High amplitude sound waves produce loud sound and low amplitude waves produce soft sound. The loudness of the sound is proportional to the square of the amplitude.

Amplitude

The loudness of sound ∝ (amplitude)^2

This is the relation between amplitude and the loudness of the sound.

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Distance from the source: As we go away from the sound source, the sensation of the sound becomes low and when we near the sound source, the sensation of the sound becomes very high. The loudness of the sound is inversely proportional to the distance from the source.

The density of the medium: The loudness of the sound depends upon the density of the medium. Sound waves travel in the air, which is how we normally experience it. However, it can also travel in liquid or solid matter. Well, it depends on how quickly the pressure wave (sound wave) can move in a given medium. The loudness of the sound is directly proportional to the density of the medium.

The loudness of the sound∝ Density of the medium.

The surface area of the vibrating body: The loudness of the sound depends upon the surface area of the vibrating body. The larger the surface of the vibrating body, the larger the loudness, and with a smaller surface of the vibrating body, the loudness becomes low.

sound

Pitch: Pitch is an important property of sound. A newborn baby who does not know anything but can sense the sound of a child easily recognizes different voices like bells, birds, his toys, and his mum’s voice or his father’s voice. How can he recognize these voices are different from each other do you imagine? Just because of the pitch, the pitch of the sound tells us how shrill or deep it is.

Commonly girl's voices are shrill and boy's voices are deep.

Shrill voice: Shrill voice has a high pitch because of a greater number of vibrations or greater frequency. It has a sharp voice. e.g., mouse squeak, hyena, and hummingbirds, etc.,

Deep or grave voice: A grave or deep voice has a low pitch because of a lower number of vibrations or a lower frequency. e.g., men’s voices are grave, and voices of lions.F

Therefore, Pitch can be defined as it is the characteristics by which we can distinguish between two sounds or the same but have different frequencies.

There are two types of pitch:

High Pitch: In physics, high pitch means greater frequency or we can also say that larger the number of vibrations. High pitch voice is known as shrill voice.
Low Pitch: Low pitch meaning is the lower frequency or smaller the number of vibrations. Low pitch voice is known as grave voice.
The main difference between high pitch and low pitch is the difference in the number of vibrations.
Intonation is known as rising and fall in the pitch.

The faster the vibration of the instrument (source), the higher the frequency, and higher is the pitch similarly, the lower the vibration of the source lower the frequency, and lower the pitch.

The pitch of the sound depends upon the vibration of sounds in one second, that is the frequency. We can determine the pitch by frequency.

Frequency: The frequency can be defined as the number of waves (or vibration of sounds) passing through one particular point in one second. The SI unit of frequency is “hertz”. It is symbolized as “Hz”. The frequency is denoted by (f).

1hz = 1 vibration/1second

There are some bigger units of Hertz to kilohertz (kHz) and megahertz (MHz).

1kHz = 10^3Hz

1MHz = 10^6Hz

A human being can hear only if the frequency lies between 20 Hz to 20,000 Hz. It is an audible frequency.
The frequency below the 20Hz is inaudible; this is known as an infrasonic sound and the frequency above the 20,000 Hz is known as ultrasonic sound.

NCERT Physics Notes:

ultrasonic and infrasonic sounds

Some of the living beings can hear ultrasonic and infrasonic sounds. Such as whistle, whistle use as an ultrasonic pitch that is too high for us but it is perfectly audible to dogs. On the other hand, elephants use infrasonic sound to communicate with each other across long distances. They can hear these sounds from several kilometers away but we cannot hear them at all.

Difference between loudness and pitch

Loudness	Pitch
The loudness of the sound depends on amplitude	the pitch of the sound is depends on the frequency .
there are two types of loudness soft sound and loud sound.	Two types of pitch high pitch and low pitch.
The loudness of the sound depends on the energy received in per unit time.	while it is independent of the energy.

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Quality: Quality can be defined as distinguishing between two sounds of the same loudness and same pitch but from different instruments.

Let’s take three instruments: tuning fork, violin, and piano. All the three instruments are played with the same loudness and same pitch but the sound of all these three instruments makes a different sound and we can easily recognize the sound of these instruments just because of the quality.

tuning fork

Tuning fork

violin

Violin

piano

Piano

1Imagine you are in a music concert where a different artist plays different types of instruments, one artist plays guitar, and one plays drums, another one plays piano, and some others sing. All these sounds travel from the same medium i.e., air, but you can easily differentiate between these instruments and the voices of the singers. All the characters of the sounds (pitch, loudness, and quality) help us to differentiate between these sounds.

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Frequently Asked Questions (FAQs)

1. How is the loudness of the sound affected by amplitude?

The amplitude of the sound waves depends upon the force with which an object is made to vibrate. High amplitude sound waves produce loud sound and low amplitude sound waves produce soft sound.

2. How is pitch affected by frequency?

Pitch is affected by frequency because the pitch is dependent upon it. The lower the frequency pitch is low and higher the frequency pitch is high.

3. On which factor the quality of sounds depends?

The waveform is the factor on which the quality of the sounds depends.

4. Why is the sound of the baby feeble?

The sound of the baby is feeble because the sound wave of the baby has low amplitude waves. As we know low amplitudes produce soft sound or we can say that feeble sound.

5. What is the sound of a lion?

Lion makes three types of sounds growl, snarl, and roar.

6. What is the difference between loudness and pitch of sound?

Loudness is the perceived intensity of a sound, while pitch is the perceived frequency of a sound. Loudness relates to the amplitude of sound waves, whereas pitch relates to the frequency of sound waves. A loud sound can have a high or low pitch, and vice versa.

7. How does the amplitude of a sound wave affect its loudness?

The amplitude of a sound wave is directly related to its loudness. Larger amplitudes result in louder sounds, while smaller amplitudes produce quieter sounds. This is because amplitude represents the amount of energy carried by the wave.

8. Can two sounds with the same amplitude have different loudness?

Yes, two sounds with the same amplitude can have different perceived loudness. This is because loudness perception also depends on factors such as frequency, duration, and the listener's hearing sensitivity. For example, the human ear is more sensitive to certain frequencies, making them seem louder.

9. What unit is used to measure loudness?

Loudness is typically measured in decibels (dB). The decibel scale is logarithmic, meaning that an increase of 10 dB represents a 10-fold increase in sound intensity. However, it's important to note that perceived loudness doesn't increase linearly with decibels.

10. How does frequency affect the perception of loudness?

The human ear is not equally sensitive to all frequencies. We perceive mid-range frequencies (around 2000-5000 Hz) as louder than very low or very high frequencies of the same intensity. This is why equalizers are used to adjust the perceived loudness of different frequency ranges in audio systems.

11. How does distance affect the loudness of a sound?

As the distance from a sound source increases, the loudness decreases. This is due to the inverse square law: sound intensity is inversely proportional to the square of the distance from the source. In practical terms, doubling the distance reduces the sound intensity by a factor of four.

12. How does background noise affect the perception of a sound's loudness?

Background noise can mask other sounds, making them seem less loud or even inaudible. This is because our auditory system has limited ability to distinguish between multiple sound sources. The louder the background noise, the more it can interfere with the perception of other sounds, even if their actual intensity hasn't changed.

13. What is the pain threshold for loudness, and why is it important?

The pain threshold for loudness is typically around 120-130 dB. It's important because sounds above this level can cause immediate damage to the ear. Prolonged exposure to sounds even well below this level (e.g., 85 dB for extended periods) can also cause hearing damage, highlighting the importance of hearing protection in noisy environments.

14. How does the structure of the ear contribute to loudness perception?

The ear's structure plays a crucial role in loudness perception. The outer ear collects and funnels sound waves. The middle ear amplifies these vibrations. In the inner ear, the cochlea's hair cells respond to different frequencies and intensities, converting mechanical vibrations into electrical signals. The brain then interprets these signals, including their intensity, as perceived loudness.

15. What is auditory adaptation, and how does it affect loudness perception?

Auditory adaptation is the process by which our perception of a constant stimulus decreases over time. For loudness, this means that a continuous sound may seem to become quieter the longer we listen to it. This adaptation helps protect our hearing and allows us to focus on new or changing sounds in our environment.

16. How do resonance and resonant frequencies affect the perceived loudness of a sound?

Resonance occurs when an object vibrates at its natural frequency. When a sound matches an object's resonant frequency, it can be amplified, potentially increasing its perceived loudness. This principle is used in musical instruments and can also explain why certain sounds seem louder in specific environments due to room acoustics.

17. What is the cocktail party effect, and how does it relate to loudness perception?

The cocktail party effect is our ability to focus on a specific voice or sound in a noisy environment. It demonstrates that loudness perception is not just about physical intensity but also involves cognitive processes. We can perceive a quieter sound (like a specific conversation) as "louder" or more prominent than objectively louder background noise when we focus our attention on it.

18. How does age affect loudness perception?

As we age, our ability to hear certain frequencies typically decreases, a condition known as presbycusis. This can affect loudness perception, especially for higher frequencies. Older individuals may perceive high-pitched sounds as less loud than younger people would, even at the same intensity level.

19. What is the role of the basilar membrane in perceiving loudness?

The basilar membrane in the cochlea plays a crucial role in loudness perception. It vibrates in response to sound waves, with different sections responding to different frequencies. The amplitude of these vibrations correlates with the intensity of the sound. Hair cells on the basilar membrane convert these mechanical vibrations into electrical signals, with stronger vibrations (from louder sounds) producing stronger electrical signals.

20. How does the Weber-Fechner law apply to loudness perception?

The Weber-Fechner law states that the perceived change in a stimulus is proportional to the logarithm of the change in the physical stimulus. For loudness, this means that we perceive equal ratios of intensity change as equal differences in loudness. This law helps explain why the decibel scale, which is logarithmic, aligns well with our perception of loudness.

21. What is meant by the "critical band" in auditory perception, and how does it relate to loudness?

A critical band is a frequency range within which sounds are processed together by the auditory system. Sounds within the same critical band can mask each other more easily, affecting loudness perception. Understanding critical bands is important for analyzing how complex sounds are perceived and for applications like audio compression and noise reduction.

22. How does binaural hearing affect loudness perception?

Binaural hearing, or hearing with two ears, enhances our perception of loudness. Sounds typically reach each ear at slightly different times and intensities. Our brain combines these inputs, often resulting in a perceived loudness that's greater than what would be experienced with monaural (single-ear) hearing. This binaural summation can make sounds seem about 3 dB louder than they would with one ear alone.

23. What is the concept of "loudness war" in music production, and how does it relate to perceived loudness?

The "loudness war" refers to the trend in music production to increase the perceived loudness of recordings. This is often done by increasing the average amplitude of the audio signal and reducing the dynamic range. While this can make a track seem louder, it can also lead to listener fatigue and reduced audio quality. This phenomenon highlights the complex relationship between signal processing, psychoacoustics, and perceived loudness.

24. How do different types of hearing loss affect loudness perception?

Different types of hearing loss can affect loudness perception in various ways. Conductive hearing loss (problems in the outer or middle ear) generally reduces the perceived loudness of all sounds equally. Sensorineural hearing loss (damage to the inner ear or auditory nerve) can result in recruitment, where sounds become disproportionately loud once they exceed the elevated hearing threshold. This can lead to a reduced dynamic range of hearing and difficulties in loudness discrimination.

25. What is the role of the olivocochlear system in loudness perception?

The olivocochlear system is a feedback mechanism in the auditory system that can modulate the sensitivity of the cochlea. It plays a role in protecting the ear from loud sounds and in improving signal detection in noisy environments. This system can effectively reduce the perceived loudness of sustained sounds, contributing to our ability to focus on specific sounds in complex auditory scenes.

26. How does the concept of "temporal integration" apply to loudness perception?

Temporal integration in loudness perception refers to how the auditory system combines sound energy over time. For short durations (up to about 200 milliseconds), the perceived loudness increases with duration even if the intensity remains constant. This is because the ear accumulates sound energy over this integration time. Beyond this duration, the perceived loudness remains relatively constant. Understanding temporal integration is crucial for accurately measuring and predicting perceived loudness, especially for short or impulsive sounds.

27. What is the concept of "specific loudness" in psychoacoustics?

Specific loudness is a measure of the contribution of different frequency bands to the overall perceived loudness of a sound. It recognizes that not all frequencies contribute equally to loudness perception. Specific loudness is typically measured in sones per bark, where sones are a unit of perceived loudness and bark is a unit of critical bandwidth. This concept is crucial in developing more accurate models of loudness perception, especially for complex sounds.

28. How does the stapedius reflex affect loudness perception?

The stapedius reflex is an involuntary contraction of the stapedius muscle in the middle ear in response to loud sounds. This reflex reduces the transmission of vibrational energy to the inner ear, effectively decreasing the perceived loudness of intense sounds. It acts as a protective mechanism against sudden loud noises and helps in improving speech intelligibility in noisy environments by attenuating low-frequency background noise.

29. What is the relationship between loudness perception and frequency masking?

Frequency masking occurs when the presence of one sound makes it difficult or impossible to hear another sound of similar frequency. This phenomenon can significantly affect loudness perception. A louder sound can mask a quieter sound if they are close in frequency, making the quieter sound seem less loud or even inaudible. Understanding frequency masking is crucial in fields like audio compression and sound design, where managing the perceived loudness of complex sound mixtures is important.

30. How does the concept of "loudness constancy" relate to our perception of sound in different environments?

Loudness constancy refers to our ability to perceive the intrinsic loudness of a sound source relatively consistently across different environments. For example, we can recognize that a person is speaking at the same volume even as they move further away, despite the actual sound intensity decreasing. This perceptual ability involves complex processing in the auditory system, taking into account factors like distance, reverberation, and environmental context to estimate the true loudness of the source.

31. What is the role of attention in loudness perception?

Attention plays a significant role in loudness perception. Sounds that we focus on can seem louder than background sounds of equal or even greater intensity. This attentional effect demonstrates that loudness perception is not solely determined by the physical properties of sound waves but is also influenced by cognitive processes. It's a key factor in phenomena like the cocktail party effect and has implications for how we design auditory interfaces and manage noise in various environments.

32. How does the concept of "loudness adaptation" differ from general auditory adaptation?

Loudness adaptation refers specifically to the decrease in perceived loudness of a constant sound over time. While general auditory adaptation can affect various aspects of sound perception, loudness adaptation focuses on the intensity aspect. This phenomenon is more pronounced for moderate sound levels and less effective for very quiet or very loud sounds. Understanding loudness adaptation is important in fields like noise control and audio design, where prolonged exposure to sounds needs to be considered.

33. How does the phenomenon of "loudness summation" affect our perception of complex sounds?

Loudness summation refers to the increase in perceived loudness when multiple sound components are present simultaneously. When two or more sounds of different frequencies are played together, the overall perceived loudness is often greater than the sum of the individual components' loudness. This effect is particularly important in understanding how we perceive complex sounds like music or environmental noise, and it plays a role in audio mixing and mastering techniques.

34. What is the concept of "loudness normalization" in digital audio, and why is it important?

Loudness normalization is the process of adjusting the overall volume of audio content to a standardized level. It's important because it helps maintain consistent perceived loudness across different audio tracks or programs, improving listener experience. This is particularly relevant in broadcasting and streaming services, where abrupt changes in loudness between different pieces of content can be jarring. Loudness normalization takes into account the complexities of human loudness perception, often using measurement standards like LUFS (Loudness Units relative to Full Scale) that better reflect how we actually perceive loudness.

35. What is the relationship between sound intensity and loudness?

Sound intensity is the amount of sound energy passing through a unit area per second, while loudness is the subjective perception of that intensity. Generally, as sound intensity increases, perceived loudness also increases, but not in a linear relationship. The relationship is logarithmic, which is why we use the decibel scale.

36. What is the threshold of hearing, and how does it relate to loudness?

The threshold of hearing is the minimum sound intensity that can be perceived by the human ear, typically around 0 dB. Sounds below this threshold are not audible. The loudness of other sounds is often compared to this threshold, with louder sounds having higher dB values.

37. Can a change in pitch affect the perceived loudness of a sound?

Yes, changes in pitch can affect perceived loudness even if the actual intensity remains constant. This is due to the varying sensitivity of the human ear to different frequencies. For example, a 1000 Hz tone might be perceived as louder than a 100 Hz tone of the same intensity.

38. What is the Fletcher-Munson curve, and how does it relate to loudness perception?

The Fletcher-Munson curve, also known as equal-loudness contours, shows how the perception of loudness varies with frequency. These curves demonstrate that the human ear is more sensitive to mid-range frequencies and less sensitive to very low and very high frequencies, affecting our perception of loudness across the frequency spectrum.

39. How does the duration of a sound affect its perceived loudness?

The duration of a sound can influence its perceived loudness. Very short sounds may be perceived as less loud than longer sounds of the same intensity. This is because our auditory system needs time to fully process and interpret the sound signal.

40. What is the difference between sound intensity level and loudness level?

Sound intensity level is an objective measure of sound energy, measured in decibels (dB). Loudness level, measured in phons, is a subjective measure that takes into account human perception and the varying sensitivity of the ear to different frequencies. A sound of 1000 Hz at 40 dB has a loudness level of 40 phons, but other frequencies may need different intensities to achieve the same perceived loudness.

41. What is meant by the "dynamic range" of human hearing in terms of loudness?

The dynamic range of human hearing refers to the range of sound intensities we can perceive, from the quietest detectable sound (0 dB, the threshold of hearing) to the loudest tolerable sound (about 120 dB, the threshold of pain). This range spans about 12 orders of magnitude in sound intensity, demonstrating the remarkable sensitivity and adaptability of our auditory system.

42. How does the logarithmic nature of the decibel scale relate to human loudness perception?

The logarithmic nature of the decibel scale closely matches how humans perceive changes in loudness. A 10 dB increase is generally perceived as about twice as loud, regardless of the starting intensity. This logarithmic relationship allows us to describe the wide range of audible intensities using a manageable scale and reflects the non-linear nature of our loudness perception.

43. What is the difference between "loudness" and "volume," and why is this distinction important?

While often used interchangeably in everyday language, "loudness" and "volume" have distinct meanings in acoustics. Loudness is a subjective perception of sound intensity, influenced by factors like frequency and individual hearing sensitivity. Volume typically refers to the physical amplitude or intensity of a sound, or the setting on an audio device. This distinction is important because changing the volume doesn't always result in a proportional change in perceived loudness, due to the complexities of human auditory perception.

44. How does the presence of harmonics affect the perceived loudness of a sound?

Harmonics, which are integer multiples of a fundamental frequency, can significantly affect perceived loudness. A sound with strong harmonics may be perceived as louder than a pure tone of the same fundamental frequency and intensity. This is partly because harmonics spread the sound energy across a wider frequency range, potentially stimulating more areas of the basilar membrane. Additionally, certain harmonic structures can create a fuller or richer sound, which might be interpreted as louder.

45. What is the significance of the "equal loudness contours" in understanding loudness perception across frequencies?

Equal loudness contours, also known as Fletcher-Munson curves, show the sound pressure levels required for sounds of different frequencies to be perceived as equally loud. These contours reveal that our ears are not equally sensitive to all frequencies, with peak sensitivity around 2-5 kHz. This information is crucial for designing audio systems, creating weighted noise measurements (like dBA), and understanding how frequency content affects perceived loudness in various applications, from music production to environmental noise assessment.

46. How does the presence of low-frequency sounds affect the overall perception of loudness?

Low-frequency sounds can significantly influence overall loudness perception, often in ways not fully captured by traditional sound level measurements. While the ear is