What is the relationship between frequency amplitude and pitch?

Answer 1

Wavelength = (speed of sound) divided by (frequency) Frequency = (speed of sound) divided by (wavelength) Amplitude is not related to frequency or wavelength. A change of amplitude does not cause ... and does not result from ... a change of frequency or wavelength

Answer 2

Frequency refers to the number of vibrations per second of a sound wave and is perceived as pitch, with higher frequencies corresponding to higher pitches. Amplitude corresponds to the intensity or volume of a sound, with louder sounds having higher amplitude. In general, higher amplitude can make a sound seem louder or more intense, but it does not directly impact pitch perception.

Answer 3

The pitch or note of a sound that we experience is determined by its wavelength or its frequency. The shorter the wavelength, the higher the frequency becomes, and the higher the pitch that we hear. The amplitude of a sound wave is the same thing as loudness. The loudness or amplitude corresponds to how much the wave is compressed. The wavelength of a wave is independent of its amplitude [loudness] and inversely proportional to its frequency.

Answer 4

Frequency and Loudness Tones of the same intensity (power per area), but of di®erent frequency, are perceived as being of di®erent loudness. To simplify the discussion, consider just sustained tones where the pressure is a sine wave. If two sounds have the same intensity and their frequencies lie between about 600 and 2000 Hertz, they will be perceived to be about the same loudness. Outside of this range, that is not the case. For sounds near 3000 to 4000 Hertz, the ear is extra-sensitive; these sounds are perceived as being louder than a 1000 Hertz sound of the same intensity. At frequencies lower than 300 Hertz, the ear becomes less sensitive; sounds with this frequency are perceived as being less loud than a sound of the same intensity and 1000 Hertz frequency. The loss of sensitivity gets bigger as one goes to lower frequencies. Also, at very high frequencies sensitivity is again reduced. Let us very brie°y explain why each of these features is present. ² Hearing below about 300 Hertz becomes ine±cient partly because the cochlea does not respond as well here, but also largely because the transmission of the vibrations through the ear bones becomes less e±cient at low frequencies. [This is a common problem with impedance matching: below some characteristic frequency of the impedance matcher, it stops working e±ciently. We might return to this after talking about resonance and impedance, when we discuss brass instruments.] ² The meatus is a tube, roughly cylindrical and of a certain length. As we will see later, such a tube has a resonant frequency, and sound waves at or near that frequency bounce back and forth several times in the tube before leaving, giving the ear a larger sensitivity to capture that sound. As we will see, the resonant wave length is ¸ = 4L with L the length of the tube. This gives a number around 3500 Hertz, and explains why the ear has a region of especially high e±ciency there. This explanation may not 1 Figure 1: Fletcher-Munson curve, showing what sounds will be perceived as equally loud. make sense to you now, but we will return to it when we talk about resonances in tubes. ² At very high frequencies one goes beyond the frequency where the cochlea is designed to work e±ciently. Also, the hair cells responsible for the highest frequencies die with age and exposure to loud sounds, so the high frequency cuto® of the ear tends to move to lower frequencies with age. We saw that it is hard to answer the question, \how many times louder is sound A than sound B?" However, it is much easier to answer, \is sound A louder, softer, or the same as sound B?" Furthermore, di®erent people will generally give the same answer for the same pair of sounds. That is, if I ¯nd a 1000 Hertz tone and a 200 Hertz tone which one person ¯nds to be of equal loudness, another person will also ¯nd them to be of equal loudness. (The exception is frequencies above 10 000 Hertz, where some peoples' ears lose sensitivity at a lower frequency than others.) Adopting 1000 Hertz sine waves as a standard, we can then ask, what intensity must a sound at 100, 200, 300, : : : Hertz be, to sound as loud as a 60 dB tone at 1000 Hertz? The answer will be a curve in a plot with frequency on the x and intensity on the y axes. We can 2 also make curves for a 50 dB tone at 1000 Hertz, a 40 dB tone at 1000 Hertz, and so forth. The ¯rst people to do this were named Fletcher and Munson, so such a curve is referred to as a Fletcher-Munson curve, and is shown in ¯gure 1. Having just advertized that di®erent people will give the same answer, I nevertheless found at least 2 Fletcher-Munson curves on the web which give slightly di®erent answers. This may be an issue of how modern the equipment used was. There is a beautiful website, linked o® the course page entry for this lecture, which lets you measure your own Fletcher-Munson curve.

Answer 5

Loudness means amplitude and pitch means frequency.

Answer 6

Frequency means pitch and amplitude means loudness.

Answer 7

Pitch is the human sensation directly related to a sound's frequency.

It's completely unrelated to amplitude.

Answer 8

Freq times Wavelength = speed of light. Amplitude in totally independent.

Answer 9

They are not.The speed of a wave is equal to the frequency times the wavelength.

The amplitude cannot be calculated, based on any of those three.

Answer 10

wave length