Amplitude and volume relationship

Pitch, Frequency, Period, Loudness, Timbre

What do pitch and volume mean when talking about sound waves? Further So, now we get the relationship between energy and amplitude. Amplitude is an objective measurement. In a waveform, it is the value of the y axis at any given point in time. Loudness is a subjective. In the volume spanned by a single wavelength, all the bits of matter are moving with . We get this thing again — the intensity-pressure amplitude relationship.

The period of a sound wave is typically measured in milliseconds. There are some optical techniques that make it possible to image the intense compressions are rarefactions associated with shock waves in air, but these are not the kinds of sounds we deal with in our everyday lives. Pressure fluctuations caused by sound waves are much easier to measure.

Animals including humans have been doing it for several hundred million years with devices called ears. Humans have also been doing it electromechanically for about a hundred years with devices called microphones. All types of amplitudes are equally valid for describing sound waves mathematically, but pressure amplitudes are the one we humans have the closest connection to.

In any case, the results of such measurements are rarely ever reported.

Instead, amplitude measurements are almost always used as the raw data in some computation. When done by an electronic circuit like the circuits in a telephone that connect to a microphone the resulting value is called intensity.

Intensity and Loudness of Sound ( Read ) | Physics | CK Foundation

When done by a neuronal circuit like the circuits in your brain that connect to your ears the resulting sensation is called loudness. The intensity of a sound wave is a combination of its rate and density of energy transfer.

It is an objective quantity associated with a wave. Loudness is a perceptual response to the physical property of intensity. It is a subjective quality associated with a wave and is a bit more complex. As a general rule the larger the amplitude, the greater the intensity, the louder the sound. Each repetition is called an oscillation: An oscillation is one segment of a repetitive motion.

Pitch, Frequency, Period Musical notes or tones have a pitch. The pitch of a particular note is often given as a number.

Now, the question is what? If you pluck a violin string tuned to Middle A, the string will vibrate or oscillate back and forth and will have a certain pitch. The technical term for pitch is frequency and the frequency referred to here is how many times in one second the string oscillates back and forth: Physicists do not like to keep write expressions out like this all of the time, so a shorthand has been developed.

Each way of writing this gets progressively more compact. Since frequency always refers to some number of oscillations, we do not have to keep writing "oscillations". Hz is an abbreviation of the unit Hertz, named after the physicists Heinrich Hertz.

How frequency and amplitude affect pitch and loudness respectively

Once we understand the meaning of a pitch or frequency of Hz, we can ask a related question: Another way to look at this is the following: Again, we have used some shorthand notation. If the period is rather small, we don't want to keep writing lots of zeros after the decimal point, so we use scientific notation, instead.

• The Nature of Sound
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This is especially convenient for sound waves, as the periods of sound waves are generally around 1 to msec. Consider the Earth going around the sun. Is this motion repetitive? What would an oscillation correspond to? What is the period and frequency of the motion?

What is the period and frequency of the wave on the following graph? Repetitive sounds can be formed in different ways. The most common, of course, is from a musical instrument. But, now, consider the situation where you are standing in front of a set of bleachers and you strike a bass drum: The individual echoes of the drum off each step are delayed from one another.

So, to the drummer the echoes form a repetitive sound which then is heard as a pitch.