Professor Greg Francis 1/6/11 PSY 200: Intro. to Cognitive Psychology 1 Purdue University Speech PSY 200 Greg Francis Lecture 30 Why do we say “razzle-dazzle” instead of “dazzle-razzle”? Purdue University Language  Many levels  grammar  phrases  words  All humans, who can, communicate through spoken language  how does language depend on speech?  what are the units of speech? Purdue University Illusions  When you hear what I say, you think you hear at least  separate words  separate syllables  But you do not  words actually overlap in the speech signal  it is nearly impossible to take a speech signal and cut it up into separate words Purdue University Illusions  The “blurriness” of speech explains some long-held confusions  Oronyms (Mondegreens) The good candy came anyways. The good can decay many ways. It’s a doggy-dog world. Purdue University Why the blur?  The ear is a bottleneck  analogous to the critical flicker frequency in the eye  the ear can distinguish <clicks> as separate only if they are given at less than 20 hertz » 20 clicks per second  above that, a series of clicks sounds like a continuous buzz Purdue University But...  Speech is seemingly perceived much better  Normal speech provides 10 to 15 distinct phonemes each second  Fast speech is 20 to 30 phonemes per second  Artificially fast speech is 40 to 50 phonemes per secondProfessor Greg Francis 1/6/11 PSY 200: Intro. to Cognitive Psychology 2 Purdue University Phonemes  pho·neme \'fo-,nem\ n [F phoneme, fr. Gk phonemat-, phonema speech sound, utterance, fr. phonein to sound](ca. 1916): a member of the set of the smallest units of speech that serve to distinguish one utterance from another in a language or dialect, the \p\ of pat and the \f\ of fat are two different phonemes in English> Purdue University Phonemes  Speech is made of phonemes  Different combinations of phonemes correspond to different syllables and words  We seemingly hear more phonemes than the ear can actually handle  how? Purdue University Packing  If the ear can only distinguish up to 20 sounds per second  and we can interpret speech that seems to contain 50 phonemes per second  then the speaker must be combining many phonemes together to overcome the limits of the ear  The listener hears the 20 (or so) sounds in a second, but interprets them as more than 20 different phonemes Purdue University Packing  If phonemes are being smashed together there must be some blurriness  and this can lead to misinterpretations  This is also why there are few computers to read to the blind  they do not know how to combine phonemes in the right way Purdue University Speech  So what are phonemes?  All speech is made of sounds  sound is a pattern of pressure on the ear  a tuning fork vibrates back and forth to make the sound of a pure tone  Frequency of vibration corresponds to pitch of the sound  Speech consists of lots of patterns of this sort  With many different overlapping frequencies Purdue University Physiology  Lungs push air out to make a sound  other organs shape soundProfessor Greg Francis 1/6/11 PSY 200: Intro. to Cognitive Psychology 3 Purdue University Example  Note where your tongue is as you say  bet butt  beet bat  The position of the tongue shapes the vocal tract and makes different sounds!  this is true for all vowels Purdue University Example  Note what your lips do as you say  boot book  The lips add additional frequencies to make different sounds  Thus, you can hear someone smile across a telephone!  Vowels are all distinguished by the shape of the vocal tract Purdue University Consonants  Consonants are more complicated  different type of control of air flow  (1) Voicing: vibration of vocal cords  /b/, /d/, /m/, /w/, /v/ (voiced)  /p/, /t/, /f/ (not voiced, or unvoiced)  (2) Place of articulation:  /d/, /t/ (upper gum)  /m/, /b/, /p/ (lips)  /f/, /v/ (lip and teeth) Purdue University Consonants  (3) Manner of articulation  /d/, /t/ (stop)  /m/ (nasal)  /f/, /v/ (fricative)  Each consonant is uniquely identified by its voice (or not) and its place and manner of articulation  Some languages have a few other characteristics as well (e.g., tone) Purdue University Fun  Why do we say razzle-dazzle instead of dazzle-razzle?  for phrases like this, people always first say the word with a leading consonant that impedes air flow the least super-duper helter-skelter harum-scarum hocus-pocus willy-nilly roly-poly holy moly herky-jerky walkie-talkie namby-pamby wing-ding mumbo-jumbo It’s a rule! Purdue University Phonemes  English uses 22-26 (it depends on how you count) combinations of voicing, place, and manner of articulation (and 20 vowels)  Rotokas (Papua New Guinea) uses 6 (and 5 vowels)  Khoisian (Bushman) uses 141 » Uses clicks as consonants  No language uses some possible sounds  raspberries, scraping teeth, squawking,…  Note, these sounds are used for communication, but not as part of language!  Japanese does not distinguish /r/ from /l/Professor Greg Francis 1/6/11 PSY 200: Intro. to Cognitive Psychology 4 Purdue University Rules  To say a word, we must combine phonemes  In every language there are rules (trees) that describe what phonemes can follow other phonemes  Thus, we can identify possible words from impossible words  plast ptak  vlas rtut  thole hlad  nypip dnom Purdue University Compression  Moving the tongue (and other articulators) around is difficult and takes time  to say sounds faster, people use coarticulation  shape tongue in advanced preparation for the next phoneme  this influences the sound of phonemes Purdue University Coarticulation  We generally do not notice these adjustments  we are tuned to recognize the new sounds as coarticulation  This is the main reason computers have a hard time recognizing human speech! Purdue University Coarticulation  Notice that your tongue body is in different positions for the two /k/ sounds in  Cape Cod  Note