1. 何謂神經性語言障礙？
腦部疾病或創傷所引致的溝通障礙統稱為神經性語言障礙，視乎腦部受損的部 份及嚴重程度，可導致失語症、失用症或構音障礙等。
2. 何謂失語症？
失語症是指由後天腦部病變或創傷而導致的溝通障礙。形成失語症的疾病包括 中風、腦炎、腦創傷、腦腫瘤等等。除了失語症外，有些病者亦可能有其他語言困難；例如面部及口腔肌肉控制不靈而說話含糊不清，或者導致構音困難症。
3. 失語症的徵狀 :
失語症病者的溝通障礙，可粗略分為理解能力及表達能力兩方面。因溝通可透過語言或文字進行，所以失語症會影響說話，聽解，書寫及閱讀等方面的表現。
(1) 說話方面: 病者可能會找不到適當的字來表達自己，出現「有口難言」或「兜圈子」的情況。有些病者會說錯字、發錯音、或用錯誤的句式結構來表達自己，甚至不由自主地重覆某些說話。有些病者說話時可以很流暢，滔滔不絕，但內容紊亂，令人有語無倫次的感覺，而無法將主題清晰地表達出來。
(2) 聽解方面: 有些病者不能牢記太長的句子，只能明白部份的內容或字眼；有些則是不懂得分析聽到的話，或因分析錯誤而誤解說話的意義。
(3) 閱讀方面: 病人可能忘記一些文字的意義或不能明白複雜的句子，也可能混淆一些意義相近或字形相似的字或詞語，以致誤解文字的內容。
(4) 書寫方面: 有些病者只能記起字的一部份，或者似閱讀時的困難，混淆了意義相關或字形相近的字，以致出現寫錯字或用錯詞，而大多病者不能書寫流暢的文章。
4. 當人們有哪些溝通障礙時，可轉介給語言治療師：
(1) 有聽力困難的現象：聽不清楚講者所說的話，或經常需要講者複述說話的內容。
(2) 有聽覺記憶力的問題：雖聽得懂講者說話的內容，但是一下子就忘了，也因此無法參與深入的話題。
(3) 有語言理解的問題：語言理解上出現了問題，例如: 聽不懂或無法完全理解抽象的語彙、較複雜的句法，或有幾個轉折的連接詞。
(4) 有說話的問題：雖然聽得懂講者的話，也知道答案，但是說話不清楚、嗓音沙啞，或是有口吃的問題，使得講者需要很費力或重複很多次，才能聽得懂其內容。
(5) 有語言表達的問題：還不太會說話，只能發一些聲音或說幾個字，或是常會說錯話。
(6) 有閱讀或書寫困難的問題：雖然聽得懂講者說話的內容，但是卻無法正確寫下來；常會寫出錯別字、部首相反或創新字等；看不懂書面資料或簡圖等視覺符號；或在圖片和文字的比對上有明顯的困難。
(7) 因生理因素造成的溝通問題: 此處是指先天或後天生理性障礙（如智能障礙、自閉症、注意力缺陷、顏面傷殘、唇顎裂、腦性麻痺等）伴隨而來的溝通問題，可能會造成語言理解、表達和說話能力的問題。
5. 兒童語言治療 :
一般兒童發音不標準的情形，稱為『構音/音韻異常』，造成異常的原因如下：
(1) 機能性構音/音韻異常：指器官上的構造及運用，都找不出任何缺陷，但是就是發音不標準。
(2) 構音器官結構上的問題，例如: 舌繫帶、唇顎裂、嚴重咬合不正。
(3) 構音器官神經肌肉控制的問題，例如: 腦性麻痺、口腔動作協調差。
(4) 感覺異常，例如: 聽力障礙、口腔靈敏度差。
(5) 智能問題，例如: 發展遲緩、智能障礙。
語言治療師說明，在幼兒3至4歲以前，構音器官的發展尚未完全成熟，語言純熟度不夠，常會出現發音不標準的情形，但隨著年齡的增長，語言發展愈來愈成熟，構音/音韻異常的情形就會自行改善。因此，當孩子到了4歲之後，仍有發音不標準的情形，則需要接受語言治療師的評估與治療。
構音/音韻異常的幼兒，接受語言治療最適當的時機，為年齡4-6歲，最好在孩子上小學一年級前完全矯正，才不會造成孩子的自卑心理或影響其人際互動。單純的機能性構音/音韻異常，只要家長與幼兒能配合，在專業的語言治療師指導下，成效通常不錯，大部分的幼兒在接受語言治療後，半年至一年內口齒清晰度會有明顯的改善，甚至可以完全發出正確的語音，若家長對孩子的發音仍然有疑問或不放心，建議找語言治療師評估是最好的方法。
何謂舌繫帶?即是所謂的『舌根』，學理上稱為『舌繫帶』，而幼兒舌繫帶是否太緊，只要觀察幼兒伸舌頭時，舌頭中線是否呈現凹陷，也就是舌頭伸出來的時候是否呈現M型，這樣就是舌繫帶太緊，或是引導幼兒做舌頭運動，看舌尖是否能碰觸上下唇，也順便觀察舌頭的活動情形。一般而言，舌繫帶通常不是造成幼兒構音/音韻異常的主要因素，可以請復健科醫師、耳鼻喉科醫師或語言治療師評估確認，以免讓孩子白挨一刀。
6. 幼兒語言發展遲緩 :
使用語言相互溝通是人類和其他物種不同的地方，但語言是經過學習而來的，如果學習過程不順利、或因特殊因素無法學習，都會造成語言發展的遲緩。就一個正常孩子來說，約10個月大時就能發出「ㄉㄚ」、「ㄇㄚ」等牙牙學語聲，約１歲開始會說爸爸、媽媽等兩個字的詞，到了2歲大時可講兩個字組合的句子。
一般而言，孩子們在兩歲到五歲之間是學習語言最快速的階段。造成語言發展障礙的先天、後天因素很多，最常引起小朋友語言發展遲緩的原因是聽力受損，然而並非每個聽力受損的孩子都會表現出一般人想像中「聽不到」的症狀，他們可能對聲音仍有反應，只是聽不清楚，以致父母親認為小朋友「聽不到」，這時必須接受聽力檢查找出病因，才能找對訓練、治療的方向。
另外，有許多孩子可能罹患了自閉症，父母親卻帶到門診抱怨：「小孩怎麼兩歲了還不太會說話？」仔細評估才發現，小朋友和別人都沒有眼神接觸，彷彿一直活在自己的世界中，而且對於某些玩具和事物相當固執，此時必須針對自閉症安排相關心理治療課程及訓練計畫，而非只是單純治療語言部份。
還有許多孩子在學習語言過程中會出現構音不準確或是口吃等問題，嚴重者也應找語言治療師協助，尋求改善。一般人常認為，舌繫帶過長會造成語言障礙，於是帶著孩子去剪舌繫帶，但事實上並非如此，絕大多數語言發展遲緩的孩子都沒有舌繫帶過長的問題。使用語言溝通是人類的重要本能，語言有障礙的兒童，不單與他人溝通會有困難，也會影響其他方面的學習，甚至不利人際關係，造成孩子自卑，不願與他人說話。因此兒童語言障礙應及早發現，接受相關專家的評估，找出潛在的病因以及最適合的治療訓練方式，愈早介入治療，改善的成效也會愈好。
7. 協助嬰幼兒語言發展的技巧 :
在日常生活環境中，父母有許多機會可以促進孩子的語言發展，只要家長能夠時時刻刻掌握一些技巧，便可以為孩子創造比較好的語言環境。
(1) 家長在和嬰幼兒說話時，速度應該保持適中，而且可以藉助誇張的表情與語調，來幫忙小朋友處理訊息。過快或過慢的說話速度對小嬰兒都是負擔，小嬰兒比較沒有辦法處理過快的訊息，對於過慢的訊息則容易抓不住重點而分心。
(2) 家長除了給予說話的刺激外，配合不同強度與不同部位的身體觸覺刺激是必要的。因為我們接收訊息不單只靠聽覺，還包括視覺、觸覺以及不同的感官知覺，如此有助於嬰幼兒更快地接收各種訊息。
(3) 不要太重視嘴形，否則反而會扭曲了語言的品質。自然的嘴形可以幫忙小嬰兒適應其他人的說話方式。
(4) 藉由模仿與停頓，幫忙小嬰兒奠定一來一往的溝通模式。父母不要急著不斷地說話，話說到一個段落或一小句，就應該給孩子反應的時間。孩子的一舉手、一投足，甚至嘴角的小動作，都可以是溝通的反應。
(5) 大人模仿小孩的聲音或動作，可以幫忙孩子知覺到自己的行為，通常孩子會受到鼓勵，發出更多的聲音或溝通性的肢體行為。
(6) 生活周遭都是話題，大人應習慣使用簡單而完整的句子來表達，小孩才會較早有句子的概念。單詞的使用要看情境，我們可以用單詞來作為強調之用，但不可以只用單詞做溝通。
(7) 對於嬰幼兒，父母可以使用手指謠、歌謠、童謠來幫助孩子學習語言。手指謠、歌謠、童謠有豐富的語調，語詞的重複性又高，再加上簡單的旋律，這些特性可以有效地幫忙嬰幼兒學習語言。大人應該掌握這些特性，抓住嬰幼兒的注意力。一般人會想放錄音帶給嬰幼兒聽就好，殊不知這會抹煞手指謠、歌謠、童謠幫忙嬰幼兒學習的特性。
8.以電影為例-《潛水鐘與蝴蝶》 (Le Scaphandre et le Papillon) :
影片片頭先以尚多明尼克•鮑比的視角開起，敘述正值42歲壯年的鮑比突然全身中風陷入昏迷，在3個禮拜後甦醒，不過被診斷出得到閉鎖症候群 (Locked-in Syndrome)，全身癱瘓僅僅剩下左眼可以活動。不過鮑比的意識清楚，在語言治療師所研發的語言表達系統下，鮑比藉由眨眼的動作透露要表達的意思。由於鮑比在病發前為時尚雜誌《ELLE》的總編輯，他曾與出版社協議要出一本書，鮑比便因此透過眨眼的動作寫下一生的回憶錄。劇情接著以鮑比的現況以及回憶交錯，描述著鮑比以往的風流韻事、與妻兒的互動、與父親的情深，以及與醫院治療師的互動情誼。
9. 心得感想:
語言使人類心智結構和功能，以及溝通能力緊密地結合一起，而正常的人類都具有講話的能力，但是任何人都必須通過學習才能獲得語言能力。使用語言相互溝通是人類和其他物種不同的地方。由於語言是經過學習而來的，如果學習過程不順利、或因特殊因素無法學習，都會造成語言發展的遲緩或障礙。零至二歲的孩子最主要的學習模仿，成人要有耐心，不斷的重複，讓孩子有模仿的機會。當小孩在零至二歲時，較注重發音，也許是無意的發聲，所以成人要引導他有意的發聲，並且不斷的重複他所發出的任何聲音。對於幼兒熟悉的字句，要多重複唸幾次，並帶領幼兒了解意思。當孩子發出聲音或達到預期，要立即給與鼓勵。這些都是幫助學齡孩子們學習語言的重要過程，任何過程都不可忽視。因此，語言治療師是個不可或缺的輔助者，若家長對孩子的發音有疑問時，醫生通常建議找語言治療師評估是最好的方法。語言治療師除了幫助孩童學習語言之外，他們也幫助有中風、腦創傷、腦腫瘤而導致有失語症之病患。
參考文獻
1語言治療服務。網址: http://www.thdf.tc.edu.tw/Site5/newfile_2.htm。
2財團法人羅慧夫顱顏基金會 語言治療。網址: http://nncf.org/face/treat_04.htm。
3周彥廷 幼兒語言發展遲緩。網址: http://www.uho.com.tw/sex.asp?sid=11&aid=4584。
4淺談兒童語言治療。網址: http://www.uho.com.tw/hotnews.asp?aid=3629。
5維基百科 潛水鐘與蝴蝶。網址: http://zh.wikipedia.org/zh-tw/%E6%BD%9B%E6%B0%B4%E9%90%98%E8%88%87%E8%9D%B4%E8%9D%B6_(%E9%9B%BB%E5%BD%B1)。
2009年10月13日 星期二
本週異國歌曲介紹: Lisa Ono - Morning
Bossa Nova:
Bossa Nova是一種融合巴西森巴舞曲和美國酷派爵士的一種「新派爵士樂」，承襲choro和samba-cancao的部分特色而又自成一格，乍聽簡潔輕快。Bossa Nova結構複雜；樂器的音階或和絃轉換的行進方式變幻莫測，往往乍聽下以為可以掌握旋律的起落和節奏，和絃一轉換後即捕足不及。它的旋律可以是行板（andante）或中板（moderato）速度進行。
語源:
Bossa Nova是葡萄牙文，Bossa是一種拉丁雙人舞節奏，Nova則是新的意思。結合起來，Bossa Nova就是一種融合了傳統巴西samba節奏與choro的一種「新派音樂」。正統的Bossa Nova的起源是南美洲巴西土生土長的音樂，之後流傳到北美洲之後廣為爵士樂壇所喜愛，由美國爵士樂手大力推廣。也因此「Bossa Nova是拉丁爵士的一種」的這個印象，已經是後來的事情了。
風格:
Bossa Nova的字面意思是「新節奏」，原來是一種拉丁音樂，聽起來輕鬆柔和、慵懶甜美、浪漫性感。與傳統南美及拉丁音樂不同的是，Bossa Nova不像Samba或Rumba那樣節奏強烈，除擁有南美音樂的熱情外，還帶有一份慵懶和輕鬆的感覺。
歷史發展:
Bossa Nova在1950年代末期的巴西興起。 1959年，由法國導演Marcel Camus執導的巴西電影「黑色奧菲斯」(Black Orpheus)勇奪康城電影節、奧斯卡、金球獎三項最佳外語片獎；帶有Bossa Nova風格的電影主題曲「A Felicidade」和「Desafinado」風行一時，人們開始對Bossa Nova產生興趣。1960年代美國更掀起一陣Bossa Nova風潮，延燒到世界各地，影響了往後1970、80年代的電影及流行音樂。踏入21世紀，Bossa Nova在台灣開始有流行的趨勢，頻頻在廣告中出現，可說是歷久彌新的「新節奏」。
歌曲連結: http://web.ezpeer.com/cd/c36552s649.html
2009年9月28日 星期一
Sound & Sound Perception
1. Sound
Analysis of sound usually treats sound as waves; in many ways, sound waves are analogous to ocean waves or ripples in water caused by dropping a stone in a pond or puddle. Sound has the following characteristics and properties which affect its perception:
Wavelength - This is the period between waves of sound and is also refered to as pitch or frequency. Expressed in Hertz (Hz), cycles per second, the human ear perceives frequencies ranging from 20 Hz to 20,000 Hz, although as humans age they tend to lose their ability to hear high frequency sounds. Hearing ranges for some animals include:
domestic cats 100-32,000 Hz
domestic dogs 40-46,000 Hz
African elephants 16-12,000 Hz
bats 1000-150,000 Hz
rodents 70-150,000 Hz
Amplitude - The volume, or loudness of a sound.
Intensity - The energy of the sound, measured in watts per square meter. Intensity is a function of the square of the amplitude, corrected for the density of the medium and at which the sound travels in the medium.
Dissipation - The loss of intensity as sound travels. One important factor in loss is the effect of spreading; as the sound spreads out over a larger area, less energy is present at any one point. Mathematically, this dissipation is described by the inverse-square law. Another cause of loss is absorption and scattering by the medium in which the sound is travelling.
Reflection & refraction - When sound hits a denser medium, some of the energy bounces, or echoes, off the surface of the denser medium. Echoes can be useful, as in the echolocation system of bats, or can result in confusing noise. When sound moves from a medium of one density to a medium of a different density, it refracts, or changes wavelength, as well. This results in distortions of the sound.
2. Six Qualities of Sound Perception
The study of sound perception is called pschoacoustics. Any time you hear or feel a sound, there are some amazing things that happen. For every sound your ear-brain system processes, you get information about:
Pitch - (also associated with frequency), the perception of a high or low sound.
Loudness - (also called amplitude), the intensity of a sound.
Phase - the increase and decrease in pressure cycle any single vibration.
Direction - (hearing with two ears creates left/right, high/low, front/back qualities), first come first heard by one ear or the other.
Distance - (also associated with reverberation time), perception of how near or far away a sound’s source is.
Timbre - (also called tone color), the perceived quality of any students’ multiple frequencies changing through time.
2.1. What is Pitch?
Pitch is the term we use to describe the psychological sensation or perception of a sound by people.
Pitch is sometimes confused with frequency, the term we use to describe the physical phenomena of sound energy created by a series of vibrations.
These are two different but complementary aspects of sound perception.
Typically, the first concept is the idea that sounds can be low or high, and that these sounds exist in a sound spectrum. Some animals hear lower than humans and some hear higher. Other natural things like ocean waves, earthquakes create ultra-low sounds (we feel it!) and a bat’s sonar creates ultra-high sounds. So this spectrum covers a wide range from 0.1 vibrations per second to over 10 million vibrations per second!
A science term for vibrations per second is Hertz, abbreviated Hz. This term is named after the German physicist Heinrich Rudolf Hertz (1857 - 1894).
2.2. What is Loudness?
Loudness is a quality defined as the intensity of sound energy as it comes in contact with an eardrum or other surface. Another term describing loudness is amplitude.
How do we measure sound intensity? We use a system called decibels based on ratios. One bel is the ratio between the differences in intensity of two sounds of 10 to 1, and a decibel is one-tenth of a bel. The bel was named after Alexander Graham Bell (1847 - 1922).
2.3. What is a Sound's Phase?
Every sound consists of an increase/decrease cycle. This cycle effects air pressure, increasing it, then decreasing it.
Scientists use positive numbers to describe the pressure increase and negative numbers to describe the decrease.
Your brain is sensitive to a sound wave's phase. Based on the subtle differences in a sound wave's phase between your two ears, your brain can tell what direction a sound came from.
Phase can be a regular pattern, like in a musical tone, or it can be irregular, like in a waterfall.
2.4. How Do We Know What Direction a Sound Comes From?
How does the loudness of a sound effect the way we locate the direction of that sound's origination?
Our auditory pathway rapidly calculates the difference in loudness between the sound as it enters both ears. In other words, a sound coming from your left side has less energy and is slightly softer by the time it reaches your right side.
What other phenomena effect the way we perceive sound?
The ambient noise level of any space or room - the mix of all of the random sounds (called masking).
Preceding - following sounds (expectation vs. surprise).
Wanted vs. unwanted sounds - our minds filter out a large portion of sound deemed unimportant. For example, a parent seemingly ignores their screaming baby while we may notice it.
2.5. What Does Distance Have to Do with Sound Perception?
Sounds have different characteristics based on how near or far they are heard from their source.
What is reverberation? All sound has a unique echo pattern created and shaped by its physical environment, whether it’s an ocean, subway, or phone booth.
Each sound has a unique echo signature based on the size and shape of the space it occurs in. For example, a gymnasium or the Grand Canyon will have much longer reverberation times than a living room because the sound bounces back and forth over a much larger area.
2.6. What is timbre (pronounces tam-ber)?
One caveat before we start! Timbre is the most complex quality of the six to understand, much less teach to someone. It combines the concepts of frequency and loudness through time. There is also an entire set of mathematics that supports these concepts related to the harmonic series.
The perceived quality of any sound, such as bright or dull, wooden or metallic, etc. is called timbre. Musicians use the term “tone color” to describe the way instruments sound together or separately. An 18th century scientist, named Joseph Fourier (1768 - 1830), proved mathematically that any sound is actually made up of a set of multiple frequencies called the harmonic series.
A Cello plays a low C - note that in practice all of these tones sound at the same time!
The lowest sounding tone is called the fundamental partial, in this example a Cello’s low C. It is the loudest tone of the series and the one we usually identify in music.
The other higher sounding partials are almost always softer, and our ear/brain system blends them together into our perception of a single tone, just as our eye/brain system blends different colors of light into our perception of white light.
心得感想:
當第二週輪到我個人做自我介紹部分時，老師補充說明sound perception概念，並且舉例佐證-「日本」的發音可以是「ni-hon」或「ni-bon」，而後者的權威意味多於前者，因此，以發音重聲來表示權威。此課堂過後，我便開始搜尋sound perception相關資料。聲音是藉由物質震動所發出的聲音，人發出聲音是藉由喉嚨聲帶的振動而發出聲音，而人之所以聽到聲音，是因為空氣震動所傳來的聲音被耳朵接收，然後耳內的耳膜產生共振，所產生的音訊再傳到腦裡，即是我們所聽到的聲音。人發出聲音和樂器很相似，舉例來說，管樂器是藉由管內空氣震動，弦樂器是靠弦震動發出聲音，而敲擊樂器是靠敲擊面震動發出聲音，例如: 把米粒放在大鼓上，然後敲鼓，就會發現米粒都在跳動。除此之外，人的發聲頻率在中頻 300-3K (HZ)，這是一般正常人發聲的界定範圍，而人耳的極限是在20Hz-20KHz(20.000Hz)。
References
1. http://www.animalbehavioronline.com/soundperception.html
2. http://www.cafemuse.com/kitchen/perception/six_qualities.html
Analysis of sound usually treats sound as waves; in many ways, sound waves are analogous to ocean waves or ripples in water caused by dropping a stone in a pond or puddle. Sound has the following characteristics and properties which affect its perception:
Wavelength - This is the period between waves of sound and is also refered to as pitch or frequency. Expressed in Hertz (Hz), cycles per second, the human ear perceives frequencies ranging from 20 Hz to 20,000 Hz, although as humans age they tend to lose their ability to hear high frequency sounds. Hearing ranges for some animals include:
domestic cats 100-32,000 Hz
domestic dogs 40-46,000 Hz
African elephants 16-12,000 Hz
bats 1000-150,000 Hz
rodents 70-150,000 Hz
Amplitude - The volume, or loudness of a sound.
In this graphical representation of a sound, the x axis is time and y axis is amplitude, or the strength of the signal. A louder sound produces higher waves, but does not change the distance between the waves. The wave makes repeated full cycles; the number of cycles completed per second is the frequency in Hertz. When a microphone or recording is played into an oscilloscope, sound is represented in this way.
Intensity - The energy of the sound, measured in watts per square meter. Intensity is a function of the square of the amplitude, corrected for the density of the medium and at which the sound travels in the medium.
Dissipation - The loss of intensity as sound travels. One important factor in loss is the effect of spreading; as the sound spreads out over a larger area, less energy is present at any one point. Mathematically, this dissipation is described by the inverse-square law. Another cause of loss is absorption and scattering by the medium in which the sound is travelling.
Reflection & refraction - When sound hits a denser medium, some of the energy bounces, or echoes, off the surface of the denser medium. Echoes can be useful, as in the echolocation system of bats, or can result in confusing noise. When sound moves from a medium of one density to a medium of a different density, it refracts, or changes wavelength, as well. This results in distortions of the sound.
2. Six Qualities of Sound Perception
The study of sound perception is called pschoacoustics. Any time you hear or feel a sound, there are some amazing things that happen. For every sound your ear-brain system processes, you get information about:
Pitch - (also associated with frequency), the perception of a high or low sound.
Loudness - (also called amplitude), the intensity of a sound.
Phase - the increase and decrease in pressure cycle any single vibration.
Direction - (hearing with two ears creates left/right, high/low, front/back qualities), first come first heard by one ear or the other.
Distance - (also associated with reverberation time), perception of how near or far away a sound’s source is.
Timbre - (also called tone color), the perceived quality of any students’ multiple frequencies changing through time.
2.1. What is Pitch?
Pitch is the term we use to describe the psychological sensation or perception of a sound by people.
Pitch is sometimes confused with frequency, the term we use to describe the physical phenomena of sound energy created by a series of vibrations.
These are two different but complementary aspects of sound perception.
Typically, the first concept is the idea that sounds can be low or high, and that these sounds exist in a sound spectrum. Some animals hear lower than humans and some hear higher. Other natural things like ocean waves, earthquakes create ultra-low sounds (we feel it!) and a bat’s sonar creates ultra-high sounds. So this spectrum covers a wide range from 0.1 vibrations per second to over 10 million vibrations per second!
A science term for vibrations per second is Hertz, abbreviated Hz. This term is named after the German physicist Heinrich Rudolf Hertz (1857 - 1894).
2.2. What is Loudness?
Loudness is a quality defined as the intensity of sound energy as it comes in contact with an eardrum or other surface. Another term describing loudness is amplitude.
How do we measure sound intensity? We use a system called decibels based on ratios. One bel is the ratio between the differences in intensity of two sounds of 10 to 1, and a decibel is one-tenth of a bel. The bel was named after Alexander Graham Bell (1847 - 1922).
2.3. What is a Sound's Phase?
Every sound consists of an increase/decrease cycle. This cycle effects air pressure, increasing it, then decreasing it.
Scientists use positive numbers to describe the pressure increase and negative numbers to describe the decrease.
Your brain is sensitive to a sound wave's phase. Based on the subtle differences in a sound wave's phase between your two ears, your brain can tell what direction a sound came from.
Phase can be a regular pattern, like in a musical tone, or it can be irregular, like in a waterfall.
2.4. How Do We Know What Direction a Sound Comes From?
How does the loudness of a sound effect the way we locate the direction of that sound's origination?
Our auditory pathway rapidly calculates the difference in loudness between the sound as it enters both ears. In other words, a sound coming from your left side has less energy and is slightly softer by the time it reaches your right side.
What other phenomena effect the way we perceive sound?
The ambient noise level of any space or room - the mix of all of the random sounds (called masking).
Preceding - following sounds (expectation vs. surprise).
Wanted vs. unwanted sounds - our minds filter out a large portion of sound deemed unimportant. For example, a parent seemingly ignores their screaming baby while we may notice it.
2.5. What Does Distance Have to Do with Sound Perception?
Sounds have different characteristics based on how near or far they are heard from their source.
What is reverberation? All sound has a unique echo pattern created and shaped by its physical environment, whether it’s an ocean, subway, or phone booth.
Each sound has a unique echo signature based on the size and shape of the space it occurs in. For example, a gymnasium or the Grand Canyon will have much longer reverberation times than a living room because the sound bounces back and forth over a much larger area.
2.6. What is timbre (pronounces tam-ber)?
One caveat before we start! Timbre is the most complex quality of the six to understand, much less teach to someone. It combines the concepts of frequency and loudness through time. There is also an entire set of mathematics that supports these concepts related to the harmonic series.
The perceived quality of any sound, such as bright or dull, wooden or metallic, etc. is called timbre. Musicians use the term “tone color” to describe the way instruments sound together or separately. An 18th century scientist, named Joseph Fourier (1768 - 1830), proved mathematically that any sound is actually made up of a set of multiple frequencies called the harmonic series.
The lowest sounding tone is called the fundamental partial, in this example a Cello’s low C. It is the loudest tone of the series and the one we usually identify in music.
The other higher sounding partials are almost always softer, and our ear/brain system blends them together into our perception of a single tone, just as our eye/brain system blends different colors of light into our perception of white light.
心得感想:
當第二週輪到我個人做自我介紹部分時，老師補充說明sound perception概念，並且舉例佐證-「日本」的發音可以是「ni-hon」或「ni-bon」，而後者的權威意味多於前者，因此，以發音重聲來表示權威。此課堂過後，我便開始搜尋sound perception相關資料。聲音是藉由物質震動所發出的聲音，人發出聲音是藉由喉嚨聲帶的振動而發出聲音，而人之所以聽到聲音，是因為空氣震動所傳來的聲音被耳朵接收，然後耳內的耳膜產生共振，所產生的音訊再傳到腦裡，即是我們所聽到的聲音。人發出聲音和樂器很相似，舉例來說，管樂器是藉由管內空氣震動，弦樂器是靠弦震動發出聲音，而敲擊樂器是靠敲擊面震動發出聲音，例如: 把米粒放在大鼓上，然後敲鼓，就會發現米粒都在跳動。除此之外，人的發聲頻率在中頻 300-3K (HZ)，這是一般正常人發聲的界定範圍，而人耳的極限是在20Hz-20KHz(20.000Hz)。
References
1. http://www.animalbehavioronline.com/soundperception.html
2. http://www.cafemuse.com/kitchen/perception/six_qualities.html
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