Final

• How does the vocal tract act as a filter?


  it resonates the source signal by allowing certain frequencies to pass through the filter with greater amplitude than other frequencies
• F2


  formant directly related to how anterior or posterior the tongue is in the mouth

  - influenced by the shape of the posterior portion of the tongue

  - more anterior, higher it is

  - more posterior, lower it is
• how does length and cross sectional area of a tube relate to the vocal tract?


  length is length and constrictions alter cross sectional area

  - ex. r distortion and speech errors
• Vowel Formant Normative Data


  natural resonant frequencies of vocal tract vary depending on the vocal tract posture

  - cannot specify absolute values

  - range of frequencies in which the relationships between formants are defined
• stress


  the amount of emphasis placed upon a segment or group for the purpose of conveying meaning

  - combination of pitch, intensity and duration

  - language defined

  - can help distinguish meaning from similar words (record, address)
• Electropalatography (EPG)

  - records the location and timing of the contact between the tongue and hard palate

  - consists of sensors imbedded in a custom-made acrylic plate called pseudopalate

  - only acquires information when the tongue is in contact with the pseudopalate

  - good for complex consonants not so good for vowels or other consonants that do not involved lingual-palatal contact

  - intrusive, may limit translation of data
• internal research validity


  certainty with which the researchers infer that a relationship between two variables is casual, or extent to which an investigation rules out alternative explanations for observed results
• basic principles of measurement

  - determine what you want to measure

  - choose correct instrumentation

  - instruments must be calibrated

  - measurement procedures must be followed

  - choose task carefully and perform it consistently

  - use instrumentation correctly
• audio recording device


  - digital recorders

  - should use external microphone for speech research (mic to mouth distance)