Determine the Frequency of Each of the Following Waveforms

Determine the Frequency of Each of the Following Waveforms

SPPA 4030

Unit 1 Homework

Answer the following questions about the plot below. The top trace is the sound pressure wave associated with the production of the phrase ‘a bad daba’. The plot immediately below traces the vertical position of the mandible.

Q1. Label the point where the mandible is in its highest position with “1”

Q2. Label the point where the mandible is in its lowest position with “2”

Q3. Circle a point where you expect the instantaneous velocity to be at or near zero.

Q4. Put a square around a point where you expect the instantaneous velocity to be very high.

Q5: Recognizing that the image quality is not optimal, determine the frequency and wavelength of each of the following sound pressure waveforms based on the time scale at the bottom of the plot.

Q6:

What is the name we give to the plot below?

What kind of sound does it represent (e.g. simple periodic, complex periodic, aperiodic)? Why?

Does this sound have a fundamental frequency. If so, what is it? What is the fundamental period?

Q7:

Q8: One the plot below, draw a line that represents the envelope associated with this sound. Is this a spectrum envelope or an amplitude envelope? How do you know?

Q9: Draw a frequency response curve for the following filters.

  1. High pass filter with cutoff frequency of 100 Hz.
  2. Low-pass filter with a cutoff frequency of 500 Hz.
  3. Band-pass filter with a lower cutoff frequency of 200 Hz and an upper cutoff frequency of 800 Hz.

Q10: You have a client who has a vocal fold paralysis. As a result of this disorder, his speech is extremely soft. One of your therapeutic goals is to increase the client’s loudness of speech. You measure the average sound pressure level of the clients speech before and after your therapy. Pre-therapy sound pressure level was 11 pressure units (actual units doesn’t matter). Post-therapy sound pressure level was 23 pressure units. Calculate the increase in sound pressure level in decibels.

Q11: Express the following pressures in dBSPL with respect to the following reference pressure.

PREF 20 micropascals

  1. 200 micropascals
  2. 10000 micropascals
  3. 20000 micropascals
  4. 200000 micropascals
  5. 2 micropascals
  6. 1 micropascal

Q12: A group of Parkinson’s patients were found to speak with an average sound pressure level of 12,000 micropascals. A group of healthy speakers spoke with an average sound pressure level of 20,000 micropascals. Express, in decibels, the difference in sound pressure level between Parkinsons’ group and the healthy control group.

Q13: For these six plots, provide the name we give to this graph type, describe what type of sound the plot represents and match those plots that are plotting similar types of sounds.

Q14: Draw an amplitude spectrum of a sound that has the same harmonic structure as the sound below, but has a different spectrum envelope.

Draw an amplitude spectrum of a sound that has the same spectrum envelope as the sound below, but has a different harmonic structure.

Q15: You measure air pressure in your mouth during speech to be 5 cm H2O above atmosphere. Is this pressure measure a vector or scalar value? Why?

Q16: Draw a pressure waveform for a sinusoid that has a frequency of 200 Hz and a peak pressure of +/- 100 micropascals. Label axes with units and a number scale.

Q17: Draw an amplitude spectrum for a sinusoid that has a period of 10 milliseconds and a peak pressure of +/- 50 micropascals. Label axes with units and a number scale.

Q18: A 30 year old singer comes to see you complaining of problems producing a high notes when singing. Her speaking voice sounds normal. You record her producing a sustained ‘ah’. Looking at the waveform of the sustained ‘ah’, you measure the fundamental period to be 5.8 milliseconds.

a. Based on our discussions in class, what kind of waveform would you expect it to be (simple periodic, complex periodic, aperiodic)?

b. To your best ability draw an amplitude spectrum for the pressure waveform associated with her /ah/ production. Label axes with units and a number scale.

Q19: What would be the wavelength of a sinusoid with a frequency of 290 Hz?

Speed of sound= 35000 cm/sec