3 Diagnostic Aud II - Acoustic Stimuli

Question 1

Why is there a perceptual difference between a note played on a flute and the same note played on a violin?

Answer 1

While they have the same fundamental frequency, the relative intensity of the harmonics are different.

Question 2

How are we able to distinguish between /i/ and /u/ spoken by the same person at the same fundamental frequency?

Answer 2

This depends on our ability to recognize which harmonics are accentuated by the resonances of the vocal tract.
-Thee formant frequencies of each of the vowels

Question 3

What are the practical implications of using regular earphones versus insert earphones in AEP testing?

Answer 3

• Ear canal collapse is less likely using inserts or circumaural phones than with standard.
• IA and minimizing external noise impact is greater with inserts.
• The delay created by the ER3A system may help minimize the impacts of electrical artifacts.
• Frequency response of inserts does not extend as far into high frequencies as TDH-50 earphones.

Question 4

What factors are involved in determining the frequency specificity of brief tones when used in AEP testing?

Answer 4

• The waveform of the stimulus including rise, fall, and plateau.
• The use of masking techniques.

Question 5

• How are clicks, brief tones (tone bursts), and chirps alike and different?
• How does the use of one over the other impact the ABR response?

Answer 5

• Both tone bursts and chirps are used to assess hearing at various frequencies during ABR testing.
• Responses to chirps are larger than to tone bursts and clicks.
• Chirps are constructed to include low frequencies prior to high frequencies whereas brief tones are each intended to test at a particular frequency.
• Clicks stimulate the entire cochlea but there is a timing delay between when the stimulus reaches various regions on the BM.