{"id":114,"date":"2020-04-29T14:14:45","date_gmt":"2020-04-29T14:14:45","guid":{"rendered":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/?post_type=chapter&#038;p=114"},"modified":"2021-09-03T17:42:43","modified_gmt":"2021-09-03T17:42:43","slug":"waves-and-wavelengths","status":"publish","type":"chapter","link":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/chapter\/waves-and-wavelengths\/","title":{"raw":"Waves and Wavelengths","rendered":"Waves and Wavelengths"},"content":{"raw":"<div class=\"PageContent-ny9bj0-0 iapMdy\">\r\n<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\"><span style=\"color: #ffffff\">Learning Objectives<\/span><\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nBy the end of this section, you will be able to:\r\n<ul>\r\n \t<li>Describe important physical features of wave forms<\/li>\r\n \t<li>Show how physical properties of sound waves are associated with perceptual experience<\/li>\r\n \t<li>Show how physical properties of light waves are associated with perceptual experience<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<p id=\"eip-818\">Visual and auditory stimuli both occur in the form of waves. Although the two stimuli are very different in terms of composition, wave forms share similar characteristics that are especially important to our visual and auditory perceptions. In this section, we describe the physical properties of the waves as well as the perceptual experiences associated with them.<\/p>\r\n\r\n<section id=\"fs-idm163523312\">\r\n<h3>Amplitude and Wavelength<\/h3>\r\n<p id=\"fs-idm59471216\">Two physical characteristics of a wave are amplitude and wavelength (<a class=\"autogenerated-content\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/5-2-waves-and-wavelengths#Figure_05_02_Wave\">Figure SAP.7<\/a>). The\u00a0<strong><span id=\"term304\">amplitude<\/span>\u00a0<\/strong>of a wave is the distance from the center line to the top point of the crest or the bottom point of the trough.\u00a0<strong><span id=\"term305\">Wavelength<\/span>\u00a0<\/strong>refers to the length of a wave from one peak to the next.<\/p>\r\n\r\n<div id=\"Figure_05_02_Wave\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"650\"]<img id=\"81053\" src=\"https:\/\/openstax.org\/resources\/eeb1fd654bf9a1980e6d4c07983fedca10a3a48b\" alt=\"A diagram illustrates the basic parts of a wave. Moving from left to right, the wavelength line begins above a straight horizontal line and falls and rises equally above and below that line. One of the areas where the wavelength line reaches its highest point is labeled \u201cPeak.\u201d A horizontal bracket, labeled \u201cWavelength,\u201d extends from this area to the next peak. One of the areas where the wavelength reaches its lowest point is labeled \u201cTrough.\u201d A vertical bracket, labeled \u201cAmplitude,\u201d extends from a \u201cPeak\u201d to a \u201cTrough.\u201d\" width=\"650\" height=\"229\" \/> Figure SAP.7 The amplitude or height of a wave is measured from the peak to the trough. The wavelength is measured from peak to peak.[\/caption]<\/figure>\r\n<p class=\"os-caption-container\"><span style=\"text-align: initial;font-size: 1em\">Wavelength is directly related to the frequency of a given wave form.\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\"><span id=\"term306\">Frequency<\/span>\u00a0<\/strong><span style=\"text-align: initial;font-size: 1em\">refers to the number of waves that pass a given point in a given time period and is often expressed in terms of\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\"><span id=\"term307\">hertz (Hz)<\/span><\/strong><span style=\"text-align: initial;font-size: 1em\">, or cycles per second. Longer wavelengths will have lower frequencies, and shorter wavelengths will have higher frequencies (<\/span><a class=\"autogenerated-content\" style=\"text-align: initial;font-size: 1em\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/5-2-waves-and-wavelengths#Figure_05_02_Frequencies\">Figure SAP.8<\/a><span style=\"text-align: initial;font-size: 1em\">).<\/span><\/p>\r\n\r\n<\/div>\r\n<div id=\"Figure_05_02_Frequencies\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"510\"]<img id=\"68063\" src=\"https:\/\/openstax.org\/resources\/e2011b502808ff751fc90883eef9ec20d3e1979d\" alt=\"Stacked vertically are 5 waves of different colors and wavelengths. The top wave is red with a long wavelengths, which indicate a low frequency. Moving downward, the color of each wave is different: orange, yellow, green, and blue. Also moving downward, the wavelengths become shorter as the frequencies increase.\" width=\"510\" height=\"171\" \/> Figure SAP.8 This figure illustrates waves of differing wavelengths\/frequencies. At the top of the figure, the red wave has a long wavelength\/short frequency. Moving from top to bottom, the wavelengths decrease and frequencies increase.[\/caption]<\/figure>\r\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1em;font-weight: bold\">Sound Waves<\/span><\/div>\r\n<\/div>\r\n<\/section><section id=\"fs-idm59549824\">\r\n<p id=\"fs-idm2640704\">The physical properties of sound waves are associated with various aspects of our perception of sound. The frequency of a sound wave is associated with our perception of that sound\u2019s\u00a0<strong><span id=\"term310\">pitch<\/span><\/strong>. High-frequency sound waves are perceived as high-pitched sounds, while low-frequency sound waves are perceived as low-pitched sounds. In humans, the audible range of sound frequencies is between 20 and 20000 Hz, with greatest sensitivity to those frequencies that fall in the middle of this range.<\/p>\r\n<p id=\"fs-idp89513280\">Other species show differences in their audible ranges. For instance, chickens have a very limited audible range, from 125 to 2000 Hz. Mice have an audible range from 1000 to 91000 Hz, and the beluga whale\u2019s audible range is from 1000 to 123000 Hz. Our pet dogs and cats have audible ranges of about 70\u201345000 Hz and 45\u201364000 Hz, respectively (Strain, 2003).<\/p>\r\n<p id=\"fs-idp9306416\">The loudness of a given sound is closely associated with the amplitude of the sound wave. Higher amplitudes are associated with louder sounds. Loudness is measured in terms of\u00a0<strong><span id=\"term311\">decibels (dB)<\/span><\/strong>, a logarithmic unit of sound intensity. A typical conversation would correlate with 60 dB; a rock concert might check in at 120 dB (<a class=\"autogenerated-content\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/5-2-waves-and-wavelengths#Figure_05_02_AudRange\">Figure SAP.9<\/a>). A whisper 5 feet away or rustling leaves are at the low end of our hearing range; sounds like a window air conditioner, a normal conversation, and even heavy traffic or a vacuum cleaner are within a tolerable range. However, there is the potential for hearing damage from about 80 dB to 130 dB: These are sounds of a food processor, power lawnmower, heavy truck (25 feet away), subway train (20 feet away), live rock music, and a jackhammer. About one-third of all hearing loss is due to noise exposure, and the louder the sound, the shorter the exposure needed to cause hearing damage (Le, Straatman, Lea, &amp; Westerberg, 2017). Listening to music through earbuds at maximum volume (around 100\u2013105 decibels) can cause noise-induced hearing loss after 15 minutes of exposure. Although listening to music at maximum volume may not seem to cause damage, it increases the risk of age-related hearing loss (Kujawa &amp; Liberman, 2006). The threshold for pain is about 130 dB, a jet plane taking off or a revolver firing at close range (Dunkle, 1982).<\/p>\r\n\r\n<div id=\"Figure_05_02_AudRange\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"975\"]<img id=\"54855\" src=\"https:\/\/openstax.org\/resources\/255ec68e0303670d7d90ced1985b7a4f83cf1373\" alt=\"This illustration has a vertical bar in the middle labeled Decibels (dB) numbered 0 to 150 in intervals from the bottom to the top. To the left of the bar, the \u201csound intensity\u201d of different sounds is labeled: \u201cHearing threshold\u201d is 0; \u201cWhisper\u201d is 30, \u201csoft music\u201d is 40, \u201cRefrigerator\u201d is 45, \u201cSafe\u201d and \u201cnormal conversation\u201d is 60, \u201cHeavy city traffic\u201d with \u201cpermanent damage after 8 hours of exposure\u201d is 85, \u201cMotorcycle\u201d with \u201cpermanent damage after 6 hours exposure\u201d is 95, \u201cEarbuds max volume\u201d with \u201cpermanent damage after 15 miutes exposure\u201d is 105, \u201cRisk of hearing loss\u201d is 110, \u201cpain threshold\u201d is 130, \u201charmful\u201d is 140, and \u201cfirearms\u201d with \u201cimmediate permanent damage\u201d is 150. To the right of the bar are photographs depicting \u201ccommon sound\u201d: At 20 decibels is a picture of rustling leaves; At 60 is two people talking, at 85 is traffic, at 105 is ear buds, at 120 is a music concert, and at 130 are jets.\" width=\"975\" height=\"848\" \/> Figure SAP.9 This figure illustrates the loudness of common sounds. (credit \"planes\": modification of work by Max Pfandl; credit \"crowd\": modification of work by Christian Holm\u00e9r; credit: \"earbuds\": modification of work by \"Skinny Guy Lover_Flickr\"\/Flickr; credit \"traffic\": modification of work by \"quinntheislander_Pixabay\"\/Pixabay; credit \"talking\": modification of work by Joi Ito; credit \"leaves\": modification of work by Aurelijus Valei\u0161a)[\/caption]<\/figure>\r\n<p class=\"os-caption-container\"><span style=\"text-align: initial;font-size: 1em\">Although wave amplitude is generally associated with loudness, there is some interaction between frequency and amplitude in our perception of loudness within the audible range. For example, a 10 Hz sound wave is inaudible no matter the amplitude of the wave. A 1000 Hz sound wave, on the other hand, would vary dramatically in terms of perceived loudness as the amplitude of the wave increased.<\/span><\/p>\r\n\r\n<\/div>\r\n<div id=\"fs-idp12758112\" class=\"psychology link-to-learning ui-has-child-title\"><header>\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\"><span style=\"color: #ffffff\">LINK TO LEARNING<\/span><\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\"><span style=\"text-align: initial;font-family: Lora, serif;font-size: 1em;font-weight: normal\">Watch this\u00a0<\/span><a style=\"text-align: initial;font-family: Lora, serif;font-size: 1em;font-weight: normal\" href=\"http:\/\/openstax.org\/l\/frequency\" target=\"_blank\" rel=\"noopener nofollow\">brief video about our perception of frequency and amplitude<\/a><span style=\"text-align: initial;font-family: Lora, serif;font-size: 1em;font-weight: normal\">\u00a0to learn more (Note: be careful using headphones when listening to this audio)<\/span><\/div>\r\n<\/div>\r\n<\/header><\/div>\r\n<p id=\"fs-idp63422528\">Of course, different musical instruments can play the same musical note at the same level of loudness, yet they still sound quite different. This is known as the timbre of a sound.\u00a0<strong><span id=\"term312\">Timbre<\/span>\u00a0<\/strong>refers to a sound\u2019s purity, and it is affected by the complex interplay of frequency, amplitude, and timing of sound waves. Sound, specifically hearing, will be discussed later in this section.<\/p>\r\n\r\n<h3>Light Waves<\/h3>\r\n<p id=\"fs-idm58596496\">The\u00a0<strong><span id=\"term308\">visible spectrum<\/span><\/strong>\u00a0is the portion of the larger\u00a0<strong><span id=\"term309\">electromagnetic spectrum<\/span><\/strong>\u00a0that we can see. As\u00a0<a class=\"autogenerated-content\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/5-2-waves-and-wavelengths#Figure_05_02_Spectrum\">Figure SAP.10<\/a>\u00a0shows, the electromagnetic spectrum encompasses all of the electromagnetic radiation that occurs in our environment and includes gamma rays, x-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. The visible spectrum in humans is associated with wavelengths that range from 380 to 740 nm\u2014a very small distance, since a nanometer (nm) is one billionth of a meter. Other species can detect other portions of the electromagnetic spectrum. For instance, honeybees can see light in the ultraviolet range (Wakakuwa, Stavenga, &amp; Arikawa, 2007), and some snakes can detect infrared radiation in addition to more traditional visual light cues (Chen, Deng, Brauth, Ding, &amp; Tang, 2012; Hartline, Kass, &amp; Loop, 1978).<\/p>\r\n\r\n<div id=\"Figure_05_02_Spectrum\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"975\"]<img id=\"61405\" src=\"https:\/\/openstax.org\/resources\/2c896faad09c7732d6326d923e3aef01cbadbc9f\" alt=\"This illustration shows the wavelength, frequency, and size of objects across the electromagnetic spectrum.. At the top, various wavelengths are given in sequence from small to large, with a parallel illustration of a wave with increasing frequency. These are the provided wavelengths, measured in meters: \u201cGamma ray 10 to the negative twelfth power,\u201d \u201cx-ray 10 to the negative tenth power,\u201d ultraviolet 10 to the negative eighth power,\u201d \u201cvisible .5 times 10 to the negative sixth power,\u201d \u201cinfrared 10 to the negative fifth power,\u201d microwave 10 to the negative second power,\u201d and \u201cradio 10 cubed.\u201dAnother section is labeled \u201cAbout the size of\u201d and lists from left to right: \u201cAtomic nuclei,\u201d \u201cAtoms,\u201d \u201cMolecules,\u201d \u201cProtozoans,\u201d \u201cPinpoints,\u201d \u201cHoneybees,\u201d \u201cHumans,\u201d and \u201cBuildings\u201d with an illustration of each . At the bottom is a line labeled \u201cFrequency\u201d with the following measurements in hertz: 10 to the powers of 20, 18, 16, 15, 12, 8, and 4. From left to right the line changes in color from purple to red with the remaining colors of the visible spectrum in between.\" width=\"975\" height=\"404\" \/> Figure SAP.10 Light that is visible to humans makes up only a small portion of the electromagnetic spectrum.[\/caption]<\/figure>\r\n<p class=\"os-caption-container\"><span style=\"text-align: initial;font-size: 1em\">In humans, light wavelength is associated with perception of colour (<\/span><a class=\"autogenerated-content\" style=\"text-align: initial;font-size: 1em\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/5-2-waves-and-wavelengths#Figure_05_02_VisSpec\">Figure SAP.11<\/a><span style=\"text-align: initial;font-size: 1em\">). Within the visible spectrum, our experience of red is associated with longer wavelengths, greens are intermediate, and blues and violets are shorter in wavelength. (An easy way to remember this is the mnemonic ROYGBIV:\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">r<\/strong><span style=\"text-align: initial;font-size: 1em\">ed,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">o<\/strong><span style=\"text-align: initial;font-size: 1em\">range,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">y<\/strong><span style=\"text-align: initial;font-size: 1em\">ellow,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">g<\/strong><span style=\"text-align: initial;font-size: 1em\">reen,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">b<\/strong><span style=\"text-align: initial;font-size: 1em\">lue,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">i<\/strong><span style=\"text-align: initial;font-size: 1em\">ndigo,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">v<\/strong><span style=\"text-align: initial;font-size: 1em\">iolet.) The amplitude of light waves is associated with our experience of brightness or intensity of colour, with larger amplitudes appearing brighter.<\/span><\/p>\r\n\r\n<\/div>\r\n<div id=\"Figure_05_02_VisSpec\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"975\"]<img id=\"35799\" src=\"https:\/\/openstax.org\/resources\/c4b39348579bd9eb5d483c570e473ccc450a5590\" alt=\"A line provides Wavelength in nanometers for \u201c400,\u201d \u201c500,\u201d \u201c600,\u201d and \u201c700\u201d nanometers. Within this line are all of the colors of the visible spectrum. Below this line, labeled from left to right are \u201cCosmic radiation,\u201d \u201cGamma rays,\u201d \u201cX-rays,\u201d \u201cUltraviolet,\u201d then a small callout area for the line above containing the colors in the visual spectrum, followed by \u201cInfrared,\u201d \u201cTerahertz radiation,\u201d \u201cRadar,\u201d \u201cTelevision and radio broadcasting,\u201d and \u201cAC circuits.\u201d\" width=\"975\" height=\"186\" \/> Figure SAP.11 Different wavelengths of light are associated with our perception of different colours. (credit: modification of work by Johannes Ahlmann)[\/caption]<\/figure>\r\n<\/div>\r\n<\/section><\/div>","rendered":"<div class=\"PageContent-ny9bj0-0 iapMdy\">\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\"><span style=\"color: #ffffff\">Learning Objectives<\/span><\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>By the end of this section, you will be able to:<\/p>\n<ul>\n<li>Describe important physical features of wave forms<\/li>\n<li>Show how physical properties of sound waves are associated with perceptual experience<\/li>\n<li>Show how physical properties of light waves are associated with perceptual experience<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p id=\"eip-818\">Visual and auditory stimuli both occur in the form of waves. Although the two stimuli are very different in terms of composition, wave forms share similar characteristics that are especially important to our visual and auditory perceptions. In this section, we describe the physical properties of the waves as well as the perceptual experiences associated with them.<\/p>\n<section id=\"fs-idm163523312\">\n<h3>Amplitude and Wavelength<\/h3>\n<p id=\"fs-idm59471216\">Two physical characteristics of a wave are amplitude and wavelength (<a class=\"autogenerated-content\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/5-2-waves-and-wavelengths#Figure_05_02_Wave\">Figure SAP.7<\/a>). The\u00a0<strong><span id=\"term304\">amplitude<\/span>\u00a0<\/strong>of a wave is the distance from the center line to the top point of the crest or the bottom point of the trough.\u00a0<strong><span id=\"term305\">Wavelength<\/span>\u00a0<\/strong>refers to the length of a wave from one peak to the next.<\/p>\n<div id=\"Figure_05_02_Wave\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 650px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"81053\" src=\"https:\/\/openstax.org\/resources\/eeb1fd654bf9a1980e6d4c07983fedca10a3a48b\" alt=\"A diagram illustrates the basic parts of a wave. Moving from left to right, the wavelength line begins above a straight horizontal line and falls and rises equally above and below that line. One of the areas where the wavelength line reaches its highest point is labeled \u201cPeak.\u201d A horizontal bracket, labeled \u201cWavelength,\u201d extends from this area to the next peak. One of the areas where the wavelength reaches its lowest point is labeled \u201cTrough.\u201d A vertical bracket, labeled \u201cAmplitude,\u201d extends from a \u201cPeak\u201d to a \u201cTrough.\u201d\" width=\"650\" height=\"229\" \/><figcaption class=\"wp-caption-text\">Figure SAP.7 The amplitude or height of a wave is measured from the peak to the trough. The wavelength is measured from peak to peak.<\/figcaption><\/figure>\n<\/figure>\n<p class=\"os-caption-container\"><span style=\"text-align: initial;font-size: 1em\">Wavelength is directly related to the frequency of a given wave form.\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\"><span id=\"term306\">Frequency<\/span>\u00a0<\/strong><span style=\"text-align: initial;font-size: 1em\">refers to the number of waves that pass a given point in a given time period and is often expressed in terms of\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\"><span id=\"term307\">hertz (Hz)<\/span><\/strong><span style=\"text-align: initial;font-size: 1em\">, or cycles per second. Longer wavelengths will have lower frequencies, and shorter wavelengths will have higher frequencies (<\/span><a class=\"autogenerated-content\" style=\"text-align: initial;font-size: 1em\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/5-2-waves-and-wavelengths#Figure_05_02_Frequencies\">Figure SAP.8<\/a><span style=\"text-align: initial;font-size: 1em\">).<\/span><\/p>\n<\/div>\n<div id=\"Figure_05_02_Frequencies\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 510px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"68063\" src=\"https:\/\/openstax.org\/resources\/e2011b502808ff751fc90883eef9ec20d3e1979d\" alt=\"Stacked vertically are 5 waves of different colors and wavelengths. The top wave is red with a long wavelengths, which indicate a low frequency. Moving downward, the color of each wave is different: orange, yellow, green, and blue. Also moving downward, the wavelengths become shorter as the frequencies increase.\" width=\"510\" height=\"171\" \/><figcaption class=\"wp-caption-text\">Figure SAP.8 This figure illustrates waves of differing wavelengths\/frequencies. At the top of the figure, the red wave has a long wavelength\/short frequency. Moving from top to bottom, the wavelengths decrease and frequencies increase.<\/figcaption><\/figure>\n<\/figure>\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1em;font-weight: bold\">Sound Waves<\/span><\/div>\n<\/div>\n<\/section>\n<section id=\"fs-idm59549824\">\n<p id=\"fs-idm2640704\">The physical properties of sound waves are associated with various aspects of our perception of sound. The frequency of a sound wave is associated with our perception of that sound\u2019s\u00a0<strong><span id=\"term310\">pitch<\/span><\/strong>. High-frequency sound waves are perceived as high-pitched sounds, while low-frequency sound waves are perceived as low-pitched sounds. In humans, the audible range of sound frequencies is between 20 and 20000 Hz, with greatest sensitivity to those frequencies that fall in the middle of this range.<\/p>\n<p id=\"fs-idp89513280\">Other species show differences in their audible ranges. For instance, chickens have a very limited audible range, from 125 to 2000 Hz. Mice have an audible range from 1000 to 91000 Hz, and the beluga whale\u2019s audible range is from 1000 to 123000 Hz. Our pet dogs and cats have audible ranges of about 70\u201345000 Hz and 45\u201364000 Hz, respectively (Strain, 2003).<\/p>\n<p id=\"fs-idp9306416\">The loudness of a given sound is closely associated with the amplitude of the sound wave. Higher amplitudes are associated with louder sounds. Loudness is measured in terms of\u00a0<strong><span id=\"term311\">decibels (dB)<\/span><\/strong>, a logarithmic unit of sound intensity. A typical conversation would correlate with 60 dB; a rock concert might check in at 120 dB (<a class=\"autogenerated-content\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/5-2-waves-and-wavelengths#Figure_05_02_AudRange\">Figure SAP.9<\/a>). A whisper 5 feet away or rustling leaves are at the low end of our hearing range; sounds like a window air conditioner, a normal conversation, and even heavy traffic or a vacuum cleaner are within a tolerable range. However, there is the potential for hearing damage from about 80 dB to 130 dB: These are sounds of a food processor, power lawnmower, heavy truck (25 feet away), subway train (20 feet away), live rock music, and a jackhammer. About one-third of all hearing loss is due to noise exposure, and the louder the sound, the shorter the exposure needed to cause hearing damage (Le, Straatman, Lea, &amp; Westerberg, 2017). Listening to music through earbuds at maximum volume (around 100\u2013105 decibels) can cause noise-induced hearing loss after 15 minutes of exposure. Although listening to music at maximum volume may not seem to cause damage, it increases the risk of age-related hearing loss (Kujawa &amp; Liberman, 2006). The threshold for pain is about 130 dB, a jet plane taking off or a revolver firing at close range (Dunkle, 1982).<\/p>\n<div id=\"Figure_05_02_AudRange\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 975px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"54855\" src=\"https:\/\/openstax.org\/resources\/255ec68e0303670d7d90ced1985b7a4f83cf1373\" alt=\"This illustration has a vertical bar in the middle labeled Decibels (dB) numbered 0 to 150 in intervals from the bottom to the top. To the left of the bar, the \u201csound intensity\u201d of different sounds is labeled: \u201cHearing threshold\u201d is 0; \u201cWhisper\u201d is 30, \u201csoft music\u201d is 40, \u201cRefrigerator\u201d is 45, \u201cSafe\u201d and \u201cnormal conversation\u201d is 60, \u201cHeavy city traffic\u201d with \u201cpermanent damage after 8 hours of exposure\u201d is 85, \u201cMotorcycle\u201d with \u201cpermanent damage after 6 hours exposure\u201d is 95, \u201cEarbuds max volume\u201d with \u201cpermanent damage after 15 miutes exposure\u201d is 105, \u201cRisk of hearing loss\u201d is 110, \u201cpain threshold\u201d is 130, \u201charmful\u201d is 140, and \u201cfirearms\u201d with \u201cimmediate permanent damage\u201d is 150. To the right of the bar are photographs depicting \u201ccommon sound\u201d: At 20 decibels is a picture of rustling leaves; At 60 is two people talking, at 85 is traffic, at 105 is ear buds, at 120 is a music concert, and at 130 are jets.\" width=\"975\" height=\"848\" \/><figcaption class=\"wp-caption-text\">Figure SAP.9 This figure illustrates the loudness of common sounds. (credit &#8220;planes&#8221;: modification of work by Max Pfandl; credit &#8220;crowd&#8221;: modification of work by Christian Holm\u00e9r; credit: &#8220;earbuds&#8221;: modification of work by &#8220;Skinny Guy Lover_Flickr&#8221;\/Flickr; credit &#8220;traffic&#8221;: modification of work by &#8220;quinntheislander_Pixabay&#8221;\/Pixabay; credit &#8220;talking&#8221;: modification of work by Joi Ito; credit &#8220;leaves&#8221;: modification of work by Aurelijus Valei\u0161a)<\/figcaption><\/figure>\n<\/figure>\n<p class=\"os-caption-container\"><span style=\"text-align: initial;font-size: 1em\">Although wave amplitude is generally associated with loudness, there is some interaction between frequency and amplitude in our perception of loudness within the audible range. For example, a 10 Hz sound wave is inaudible no matter the amplitude of the wave. A 1000 Hz sound wave, on the other hand, would vary dramatically in terms of perceived loudness as the amplitude of the wave increased.<\/span><\/p>\n<\/div>\n<div id=\"fs-idp12758112\" class=\"psychology link-to-learning ui-has-child-title\">\n<header>\n<div class=\"textbox textbox--key-takeaways\"><\/div>\n<\/header>\n<header class=\"textbox__header\">\n<p class=\"textbox__title\"><span style=\"color: #ffffff\">LINK TO LEARNING<\/span><\/p>\n<\/header>\n<div class=\"textbox__content\"><span style=\"text-align: initial;font-family: Lora, serif;font-size: 1em;font-weight: normal\">Watch this\u00a0<\/span><a style=\"text-align: initial;font-family: Lora, serif;font-size: 1em;font-weight: normal\" href=\"http:\/\/openstax.org\/l\/frequency\" target=\"_blank\" rel=\"noopener nofollow\">brief video about our perception of frequency and amplitude<\/a><span style=\"text-align: initial;font-family: Lora, serif;font-size: 1em;font-weight: normal\">\u00a0to learn more (Note: be careful using headphones when listening to this audio)<\/span><\/div>\n<\/div>\n<\/section>\n<\/div>\n<p id=\"fs-idp63422528\">Of course, different musical instruments can play the same musical note at the same level of loudness, yet they still sound quite different. This is known as the timbre of a sound.\u00a0<strong><span id=\"term312\">Timbre<\/span>\u00a0<\/strong>refers to a sound\u2019s purity, and it is affected by the complex interplay of frequency, amplitude, and timing of sound waves. Sound, specifically hearing, will be discussed later in this section.<\/p>\n<h3>Light Waves<\/h3>\n<p id=\"fs-idm58596496\">The\u00a0<strong><span id=\"term308\">visible spectrum<\/span><\/strong>\u00a0is the portion of the larger\u00a0<strong><span id=\"term309\">electromagnetic spectrum<\/span><\/strong>\u00a0that we can see. As\u00a0<a class=\"autogenerated-content\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/5-2-waves-and-wavelengths#Figure_05_02_Spectrum\">Figure SAP.10<\/a>\u00a0shows, the electromagnetic spectrum encompasses all of the electromagnetic radiation that occurs in our environment and includes gamma rays, x-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. The visible spectrum in humans is associated with wavelengths that range from 380 to 740 nm\u2014a very small distance, since a nanometer (nm) is one billionth of a meter. Other species can detect other portions of the electromagnetic spectrum. For instance, honeybees can see light in the ultraviolet range (Wakakuwa, Stavenga, &amp; Arikawa, 2007), and some snakes can detect infrared radiation in addition to more traditional visual light cues (Chen, Deng, Brauth, Ding, &amp; Tang, 2012; Hartline, Kass, &amp; Loop, 1978).<\/p>\n<div id=\"Figure_05_02_Spectrum\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 975px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"61405\" src=\"https:\/\/openstax.org\/resources\/2c896faad09c7732d6326d923e3aef01cbadbc9f\" alt=\"This illustration shows the wavelength, frequency, and size of objects across the electromagnetic spectrum.. At the top, various wavelengths are given in sequence from small to large, with a parallel illustration of a wave with increasing frequency. These are the provided wavelengths, measured in meters: \u201cGamma ray 10 to the negative twelfth power,\u201d \u201cx-ray 10 to the negative tenth power,\u201d ultraviolet 10 to the negative eighth power,\u201d \u201cvisible .5 times 10 to the negative sixth power,\u201d \u201cinfrared 10 to the negative fifth power,\u201d microwave 10 to the negative second power,\u201d and \u201cradio 10 cubed.\u201dAnother section is labeled \u201cAbout the size of\u201d and lists from left to right: \u201cAtomic nuclei,\u201d \u201cAtoms,\u201d \u201cMolecules,\u201d \u201cProtozoans,\u201d \u201cPinpoints,\u201d \u201cHoneybees,\u201d \u201cHumans,\u201d and \u201cBuildings\u201d with an illustration of each . At the bottom is a line labeled \u201cFrequency\u201d with the following measurements in hertz: 10 to the powers of 20, 18, 16, 15, 12, 8, and 4. From left to right the line changes in color from purple to red with the remaining colors of the visible spectrum in between.\" width=\"975\" height=\"404\" \/><figcaption class=\"wp-caption-text\">Figure SAP.10 Light that is visible to humans makes up only a small portion of the electromagnetic spectrum.<\/figcaption><\/figure>\n<\/figure>\n<p class=\"os-caption-container\"><span style=\"text-align: initial;font-size: 1em\">In humans, light wavelength is associated with perception of colour (<\/span><a class=\"autogenerated-content\" style=\"text-align: initial;font-size: 1em\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/5-2-waves-and-wavelengths#Figure_05_02_VisSpec\">Figure SAP.11<\/a><span style=\"text-align: initial;font-size: 1em\">). Within the visible spectrum, our experience of red is associated with longer wavelengths, greens are intermediate, and blues and violets are shorter in wavelength. (An easy way to remember this is the mnemonic ROYGBIV:\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">r<\/strong><span style=\"text-align: initial;font-size: 1em\">ed,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">o<\/strong><span style=\"text-align: initial;font-size: 1em\">range,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">y<\/strong><span style=\"text-align: initial;font-size: 1em\">ellow,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">g<\/strong><span style=\"text-align: initial;font-size: 1em\">reen,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">b<\/strong><span style=\"text-align: initial;font-size: 1em\">lue,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">i<\/strong><span style=\"text-align: initial;font-size: 1em\">ndigo,\u00a0<\/span><strong style=\"text-align: initial;font-size: 1em\">v<\/strong><span style=\"text-align: initial;font-size: 1em\">iolet.) The amplitude of light waves is associated with our experience of brightness or intensity of colour, with larger amplitudes appearing brighter.<\/span><\/p>\n<\/div>\n<div id=\"Figure_05_02_VisSpec\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 975px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"35799\" src=\"https:\/\/openstax.org\/resources\/c4b39348579bd9eb5d483c570e473ccc450a5590\" alt=\"A line provides Wavelength in nanometers for \u201c400,\u201d \u201c500,\u201d \u201c600,\u201d and \u201c700\u201d nanometers. Within this line are all of the colors of the visible spectrum. Below this line, labeled from left to right are \u201cCosmic radiation,\u201d \u201cGamma rays,\u201d \u201cX-rays,\u201d \u201cUltraviolet,\u201d then a small callout area for the line above containing the colors in the visual spectrum, followed by \u201cInfrared,\u201d \u201cTerahertz radiation,\u201d \u201cRadar,\u201d \u201cTelevision and radio broadcasting,\u201d and \u201cAC circuits.\u201d\" width=\"975\" height=\"186\" \/><figcaption class=\"wp-caption-text\">Figure SAP.11 Different wavelengths of light are associated with our perception of different colours. (credit: modification of work by Johannes Ahlmann)<\/figcaption><\/figure>\n<\/figure>\n<\/div>\n","protected":false},"author":13,"menu_order":9,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"part":27,"_links":{"self":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters\/114"}],"collection":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/users\/13"}],"version-history":[{"count":11,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters\/114\/revisions"}],"predecessor-version":[{"id":2068,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters\/114\/revisions\/2068"}],"part":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/parts\/27"}],"metadata":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters\/114\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/media?parent=114"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapter-type?post=114"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/contributor?post=114"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/license?post=114"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}