Changing Fundamental Frequency and Intensity

Question 1

How to increase fundamental frequency? Why does this work?

Answer 1

• Mass
• Length
• Stiffness
• Contraction of Cricothyroid muscles
• Contraction of Thyroarytenoid muscles
• Laryngeal elevation via thyrohyoid muscles
  
  • Thought to further increase the stiffness of the vocal folds
  • Elevation of the larynx may result in downward pull on the underside of the vocal folds
  • F0 increases
• Laryngeal depression via sternothyroid and sternyhyoid
  
  • Thought to further decrease the stiffness of the vocal folds
  • Removes some of the usual traction on the underside of the vocal folds
  • F0 decreases

Question 2

How to increase intensity? Why does this work?

Answer 2

• Below the glottis
  
  • Alter subglottal pressure
  • Increasing subglottal pressure results in increasing intensity
  • Decreasing subglottal pressure results in decreasing intensity
  • Increased Ps
  • Increased driving force – vocal folds blown apart more forcefully
  • Leads to greater lateral excursion of vocal folds
  • Leads to faster/harder recoil back to rest
  • Recoil force is proportional to distorting force
  • When vocal folds come together forcefully, there is more energy in the voice signal and greater intensity
• At the glottis
  
  • Changing stiffness of the vocal folds
  • Varying the degree of glottal opening and closing
  • Changing stiffness of the vocal folds
  • Increasing stiffness of the vocal folds can cause an increase in Ps
  • Intensity will increase
  • Because stiffer folds are harder to blow apart
  • Generally an increase in intensity is accompanied by a small increase in F0
• Above the glottis
  
  • Vocal tract in a more open position
  • Velum (soft palate and uvula) elevates
  • Mouth opens wider
  • Tongue lowers
  • Intensity will increase
  • Less important than subglottal and glottal mechanisms

Question 3

• Fundamental Frequency
• Intensity

(perceptual correlates and units)

Answer 3

• Pitch // Hz
• Volume // dB

Question 4

How to calculate F0?

Period of vocal fold vibration = 9.2 ms

Answer 4

• F0 = 1/period of 1 cycle of vibration (p)
• A period is the amount of time (in seconds or milliseconds) needed to complete one cycle of vibration
• Period of vocal fold vibration (p) = 1/F0
  
  • F0 = 1/p
  • F0 = 1/9.2ms
  • F0 = 1/0.0092s
  • F0 = 108.7 Hz

Question 5

Typical F0s for men, women, children, and infants?

Answer 5

• Men: 70-140 Hz
• Women: 140-280 Hz
• Children(male or female): 280-560 Hz
• Infant cry: 600 Hz