Module 2 Speech Science Short Questions + Answers

If the rate of vibration of the vocal folds (fundamental frequency, f) is 180 Hz, what is the period (T) of the glottal cycle? Show your calculation and report your answer in seconds and milliseconds.

The period is the reciprocal of frequency: T = 1/f, T = 1/180 Hz, T = 0.00556 seconds, T = 5.56 milliseconds

What happens to speech when helium is inhaled, and why? Discuss the acoustic and aerodynamic principles involved in voice production, including how helium affects the transmission of sound through the vocal tract and the resulting changes in speech quality.

Helium causes speech to sound unusually high-pitched or "squeaky," although the fundamental frequency of vocal fold vibration changes little. Because helium is less dense than air, sound travels through the vocal tract more rapidly, causing the resonant frequencies (formants) of the vocal tract to increase. These altered resonance characteristics change speech quality and make the voice sound higher. The primary effect is acoustic rather than aerodynamic.

Research a pioneer scientist in the history of speech science and describe a brief vignette from their life or work. Explain their major contribution, how it advanced the understanding of speech, hearing, or acoustics, and why it remains important today.

Answers will vary. EXAMPLE Abū l-Fatḥ ʿUthmān ibn Jinnī (c. 940–1002 AD), widely known as Ibn Jinni, was a Muslim white male, one of the most influential Arab linguists in history. The name Jinni in Greek means noble birth. Through his detailed analysis of Arabic phonetics, morphology, and grammar, he made important contributions to the field of speech science. In his most notable work, Al-Khasais, Ibn Jinni examined the relationship between sound and meaning, which is consistent with the modern phonological theory. He contributed to the understanding of linguistic theory and the processing of language through his insights on articulation, sound classification, and the structure of Arabic grammar. The works of Ibn Jinni not only advanced Arabic linguistics but also laid the groundwork for later developments in speech science and philology. Studies of language and speech, both historically and in the present day, are impacted by his intellectual legacy. As part of his work, he systematically related linguistic elements to their social and cultural contexts, emphasizing how language is influenced by social factors. This theory established the foundation for the development of semantic studies in Arabic, showing how language elements are interconnected with cultural contexts and nuances, leading to a deeper understanding of speech and language structure scientifically. His study on syntax helps the research in the scientific study of speech patterns. 

Orient yourself to the nasal airflow tracing below from a nasometer. The tracing was recorded during production of the sentence, “Sally cooked rice.” The Y-axis shows the amount of nasalance present. (a) What can you conclude from this airflow tracing? (b) Could this tracing have been produced by someone with an abnormally short velum? and (c) Imagine this tracing was produced by a child who recently had their nasopharyngeal tonsils, or adenoids, surgically removed. What might you conclude?

(a) The tracing suggests a continuous velopharyngeal leak because nasalance never returns to zero. Nasalance increases during high-pressure consonants such as /s/ and /k/.  (b) Yes. An abnormally short velum could prevent complete velopharyngeal closure and produce this pattern.  (c) The adenoids may have been assisting velopharyngeal closure prior to surgery. Following adenoid removal, the child may experience temporary velopharyngeal insufficiency. Over time, compensatory adjustments may improve closure.

In a Helmholtz resonator, indicate whether the resonant frequency would increase or decrease for each of the following changes. Briefly explain your reasoning.(a) The volume of the resonator bowl (cavity) is decreased. and (b) The length of the neck (port) is decreased.

 (a) Increase. A smaller cavity volume results in a higher resonant frequency because the air in the cavity is less compliant.  (b) Increase. A shorter neck reduces the vibrating air mass, allowing the system to oscillate at a higher frequency.

Discuss at least three ways vibratory energy can be lost as sound travels through the vocal tract.

• Frictional losses as sound waves interact with vocal tract surfaces.

• Thermal losses as acoustic energy is converted into heat.

• Radiation losses as sound energy radiates from the lips and nostrils.

• Absorption by soft tissues of the vocal tract.

• Energy loss through the nasal cavity when the velopharyngeal port is open.