Exam Question Checklist

Exam 1999 Question 6

"Describe how distributions of fundamental frequency use may be obtained from laryngographic analysis. Discuss the problems of obtaining a reliable indication of fundamental frequency range from laryngographic analysis. Discuss the relative advantages of the laryngograph over narrow-band spectrograms for the study of intonation contours."

20 things you should mention:

• Laryngograph
  • Lx waveform for monitoring current flow
  • Tx = individual period estimates
  • Fx = calculated from Tx of each cycle
  • can have Fx display versus time
  • build a histogram of Fx usage
  • from (say) a read passage
  • Dx1 includes all frequencies
  • Dx2 includes only regular voicing
  • Cx shows regular and irregular
  • - pictures
• Range problems
  • standard deviation problems
  • - affected by outliers
  • outliers caused by low-frequency creak (typically)
  • better to use percentile-based measures
  • 90% range better
  • measuring max-min on Fx display also susceptible to errors
• c.f. Spectrogram
  • spectrograph: contaminated by noise
  • difficult to see harmonics for low-pitched voice, can't get period-by-period estimates
  • doesn't need special equipment
  • direct, reliable, automated analysis