Frequency-Following Response to Voice Pitch: Fundamentals and Clinical Implications

1. Frequency-Following Response to Voice Pitch: Fundamentals and Clinical Implications Fuh-Cherng Jeng, MD, PhD Auditory Electrophysiology Laboratory http://oak.cats.ohiou.edu/~jeng/ November 12, 2010

2. Importance of voice pitch !

3. Electrophysiological measures inauditory research What can evoked-potential measures tell us? How can that information help the clinic? Why are normal-hearing listeners used? evoked potential recording system listener acoustic stimulus + - time

4. BackgroundAuditory Evoked Potentials • Auditory brainstem response (ABR) • Middle-latency response (MLR) • Late-latency response (LLR) • Mismatch negativity (MMN) • Cognitive response (P300) • Auditory steady-state response (ASSR)

5. BackgroundFrequency Following Response (FFR) • Follows the periodicity (i.e., frequency content) of the stimulus. • Phase locked to the periodicity of the stimulus f0 and harmonics • Originates from the brainstem area Period = 0.02 sec Frequency = 1/0.02 sec = 500 Hz Moushegian et al., 1973

6. BackgroundRecent accomplishment • Pitch encoding at the human brainstem correlates with listeners’ linguistic experience. -Krishnan et al., 2005 • Musical training shapes brainstem encoding of linguistic pitch patterns. -Wong et al., 2007, Nature Neuroscience • Some Autism children show compromised pitch tracking accuracy. –Russo et al., 2008 • Pitch encoding at the brainstem is related with reading and speech-in-noise perception. –Hornickel et al., 2009

7. Project 1: NeonatesDear baby, can you hear me?

8. Project 1: Neonates Goals and Hypotheses • Goals • Investigate the characteristics of FFR to voice pitch in neonates (1-3 days old). • Examine the relative contributions of the “biological capacity” versus “linguistic experience” influences on pitch processing at the human brainstem. • Hypotheses • Based on the “biological capacity” model, neonates will demonstrate accurate processing of voice pitch during the first few days after birth. • Based on the “linguistic experience” model, enhancement of the FFR to voice pitch will be expected as a result of exposure to a specific language environment.

9. Project 1: NeonatesMethods: Quantitative analysis /i2/

10. Project 1: NeonatesFrequency Error Frequency Error

11. Project 1: NeonatesSlope Error Slope Error is the difference of the slope estimates between the stimulus and response f0 contours Slope of stimulus f0 contour Slope of response f0 contour

12. Project 1: NeonatesTracking Accuracy • Tracking Accuracy is the regression r value between the stimulus and response f0 contours

13. Project 1: NeonatesPitch Strength • Pitch Strength is the peak-to-trough amplitude in the normalized autocorrelation output

14. Project 1: NeonatesRaw data Stimulus Response Control

15. Project 1: NeonatesAmerican neonates

16. Project 1: NeonatesChinese neonates

17. Project 1: Neonates Cross-linguistic comparison -Jeng et al., Ear and Hearing, under review

18. Project 2: InfantsAny change during the first year?

19. Project 2: InfantsRaw data Stimulus Response Control

20. Project 2: InfantsIndividual infants

21. Project 2: InfantsLongitudinal follow-up

22. Project 2: InfantsDevelopmental trend -Jeng et al., in press (a)

23. Project 3: Automation Can we make the procedures automated? Stimulus Response Control

24. Project 3: AutomationResponse threshold Distribution of recordings obtained in experimental condition Response threshold Distribution of recordings obtained in control condition

25. Project 3: AutomationTwo algorithms across four tones Short-Term Autocorrelation Narrow-Band Spectrogram

26. Project 3: AutomationSensitivity & specificity

27. Project 3: AutomationReceiver operating characteristics (ROC) -Jeng et al., in press (b)

28. Project 4: ModelingExponential model Time constant () Number of sweeps

29. Project 4: ModelingNumber of sweeps means TIME!!!

30. Project 4: ModelingThree different stimulus intensities

31. Project 4: ModelingFFR trends Number of sweeps Number of sweeps

32. Project 4: ModelingCurve fitting

33. Project 4: ModelingFour indices at three stimulus intensities

34. Project 4: ModelingTime constant () = number of sweeps needed -Jeng et al., under revision

35. Project 5: NoiseHow much noise can the listener tolerate?

36. Project 5: NoiseRaw data

37. Project 5: NoiseNoise tolerance at about 0-6 dB SNR -Ximing Li & Fuh-Cherng Jeng, JASA EL, under revision

38. Future directions • Continue, expand and better define the FFR to voice pitch in normal and pathological populations • Cross-linguistic comparison, longitudinal follow-up • Automation and modeling of the FFR to voice pitch in neonates and infants • Integration with behavioral responses

39. AcknowledgmentsAuditory Electrophysiology Laboratory

40. Questions?

41. Project 5: f0-HarmonicsRelative contributions of the f0 and its harmonics?

42. Project 5: f0-Harmonics American adults

43. Project 5: f0-Harmonics Chinese adults

44. Project 5: f0-Harmonics Group comparison -Jeng et al., under revision