1. CD 491: Audiology Lecture 2 Clinical Applications

2. How do we measure hearing ? How do we know what’s normal? How do we know what is a HL?

3. Decibels Decibel: a unit for expressing the ratio between 2 sound pressures Represents a Ratio Logarithm Nonlinear Several reference levels SPL HL SL

4. Absolute Threshold of human hearing (actually varies) across frequencies Different SPL values at different frequencies Which sounds can humans hear better? What pitches are harder for humans to hear?

5. Real ear thresholds in SPL- human hearing across frequency

6. Range of Human Hearing Detection Threshold = 0 dB Does this vary with frequency? Threshold of Feeling = 130 dB Does this vary with frequency?

7. What is the amount of dB SPL that it takes to detect a signal of 1000 Hz? 1. 9 dB SPL 2. 7 dB SPL 3. 9 dB HL 4. 7 dB HL

8. Decibels - Hearing Level (HL) In NH listeners, different amounts of SPL are needed at different frequencies for detection. Defined a new scale “hearing level” (HL): The lowest sound intensity that stimulates normal hearing is “zero Hearing Level” Audiometers are calibrated in dB HL using dB SPL as a reference So, what does 0dB HL mean?

9. What is Audiometric Zero? Level of a pure tone for a given frequency that is minimally detectable by a person with normal hearing = audiometric 0 When audiometer built the reference had to be in terms of SPL values and converted to 0 dB HL…

10. Audiogram not using Audiometric Zero Audiogram using Audiometric Zero as reference

11. Audiograms – Hearing Level dB HL

12. Sensation Level dB SL = dB Sensation Level Reference - Uses person’s own threshold as a reference Example:

13. Standard output levels lfor 0 dB HL (see text Table 2.5) If audiometer set at 0 dB HL (assume TDH – 39) Output at 500 Hz? Output at 1000 Hz? Output at 2000 Hz? Output at 4000 Hz?

14. When measuring hearing thresholds in humans, all frequencies can be detected (SPL) equally. 1. True 2. False

15. dB SPL, dB HL and dB SL can all be used to measure hearing? 1. True 2. False

16. Which was not a reason that the dB HL scale was created was to... 1. To show that 0 dB means nothing 2. To provide a level baseline 3. Because the range of human hearing was too large 4. Provide an easier way to illustrate test results

17. Pathways for sound

19. Air and Bone Relationship

21. Audiograms

22. Other speech sounds on Audiograms

24. Audiometric symbols

25. Plot AC for the following values accordingly RELE 2505020 5004525 10004065 20003075 40004080 80005080

26. Plot AC for the following values accordingly on SAME audiogram RELE 25025-5 500400 1000355 2000305 4000100 800050

27. Plot AC and BC for the following values accordingly RE BC LE BC 2501015 5004010 10003510 2000405 4000400 8000DNT

28. Plot AC and BC for the following values accordingly RE AC LE AC RE BC LE BC 25015 10150 50020152010 100025502550 200035653060 400040803570 8000809070NR

29. Speech sounds available by Frequency

30. What does this graph mean?

32. Low Mid High

33. Speech Cues of Consonants

34. Voicing

35. Suprasegmental An effect on speech as length stress tone and aspiration that extends over one segment of sounds.

36. F1, F2, F3 of Vowels

37. Nasality Vowels are described as being purely oral or nasalized Nasal consonants is that the air escapes through the nose

38. Fricatives/Affricates Fricatives: Consonants that when they are produced the air escapes through a small passage and makes a hissing sound Affricates: are complex consonants. They begin as plosives and end as fricatives. (search)

39. Plosives There are 6 plosive consonants in English formed by complete closure of the air passage which is afterwards released suddenly. p/b, t/d, k/g

40. 1 minute evaluation What was the most important thing you remember learning today? What one question would you like reviewed related to what was discussed ? What can you apply when you leave this room?