How is loudness related to the amplitude of a sound wave

The speed of a wave is only altered by alterations in the properties of the medium through which it travels. The wavelength of a wave does not affect the speed at which the wave travels. The amplitude of the sound wave states the loudness of sound. The change in amplitude of the sound wave does not affect the speed of the sound wave. The speed of sound can be affected by the properties of the medium through which it is traveling.

Amplitude and sound are directly proportional. The amplitude of the wave determines the loudness of a sound wave. A larger amplitude means a loud sound while a smaller amplitude means a soft sound. If the amplitude is high then the sound will be louder and the sound will be feeble if the amplitude is low. Amplitude does not affect wavelength. Sound waves can only travel through a solid, liquid or gas. When an object or substance vibrates, it produces sound.

The bigger the vibrations, the greater the amplitude and the louder the sound. A microphone converts sound energy into electrical energy in the form of electronic signals. A computer or an oscilloscope can be used to display these electronic signals, which show the same changes in amplitude and frequency as the sound waves. When these signals are observed on the oscilloscope, the oscilloscope pattern will indicate the same changes in amplitude and frequency which correspond to the wave's loudness and pitch frequency.

For example, the loudest sound that the ear can safely detect without suffering any physical damage is more that one billion times more intense than the threshold of hearing where sounds can just be heard.

The ear responds to sounds of different loudness in such a way that huge increases in amplitude are registered as small increases in loudness.

To match this way in which the ear responds, the relative loudness of sounds is usually measured in decibels. The decibel scale, which is a logarithmic scale, stretches from 0 dB at the threshold of hearing to dB at the threshold of pain values vary, as this is subjective — pain is not a precisely defined experience. Each time you go up one decibel, the loudness of the sound increases by a constant factor and you can just about hear this change.

Logarithmic intensity scales are also used to report on the perceived brightness of light the sensitivity of the eye is also logarithmic and for measuring the strength of earthquakes the Richter scale.

A Physics Narrative presents a storyline, showing a coherent path through a topic The loudness of a sound relates the intensity of any given sound to the intensity at the threshold of hearing.

It is measured in decibels dB. The threshold of human hearing has an intensity of about. The threshold of pain for humans is 1 Watt per meter squared and corresponds to dB. A whisper is between 20 and 30 dB, noisy conversation is about 50 dB, a vacuum cleaner is about 70 dB, a lawn mower is about 90 dB and a car horn at 1 m is about dB. Humans are particularly sensitive to sounds ranging in frequency between and Hertz.

The dBA scale has a filter so the sound level meter is less sensitive to low and high frequency sounds just like human hearing. It is also better adapted to measuring hearing damage and speech interference in humans. Noise affects the natural environment. For example, extra sounds cause "auditory masking" which reduces an animal's ability to detect communications and predators. Some birds sing at a higher pitch in noisier areas.

Because female birds of certain species prefer males singing at a lower pitch since it denotes maturity, this may lead to reduced bird populations. Other birds may just sing louder in noisy areas. Chinese frogs have even shifted their calls to the ultrasonic range above the frequencies humans can hear so they can locate each other during mating season. Gleaning bats those that pluck insects from leaves will not hunt in noisy areas.

Noise also "stresses" wildlife making them less resistant to disease. Noise definitely affects aquatic environments.