1 / 14

Pitch Contour Following Response (PCFR) in Infants

Pitch Contour Following Response (PCFR) in Infants. By: Elizabeth Schnabel Advised By: Dr. Jeng. Overview. Introduction Methods Results Discussion References. Introduction. PCFR – Pitch Contour Following Response A Frequency Following Response (FFR)

todd
Download Presentation

Pitch Contour Following Response (PCFR) in Infants

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Pitch Contour Following Response (PCFR) in Infants By: Elizabeth Schnabel Advised By: Dr. Jeng

  2. Overview • Introduction • Methods • Results • Discussion • References

  3. Introduction • PCFR – Pitch Contour Following Response • A Frequency Following Response (FFR) • Follows the spectral changes in the stimuli.

  4. FFR – Frequency Following Response • Series of sinusoidal peaks – intervals between peaks are phase-locked to the period of the stimulus harmonics • Response from the lower brainstem • Non-invasive insight into the brain’s ability to perceive the Fundamental Frequency of speech. (Moushegian et al., 1973)

  5. Initial Studies Investigated: FFR’s ability to preserve vowel harmonic information. - by presenting a steady state of synthetic approximations of English back vowels. (Krishnan, 2002)

  6. Recent Studies Yi1 Yi2 Yi3 Yi4 hum Investigated: FFR’s ability to follow harmonic tonal change in a stimulus - PCFR • English language tonal change can change the meaning of a phrase. • Tonal languages tonal change can change a single word meaning. Krishnan et al. (2004)

  7. Questions/Hypothesis • (1) Is PCFR able to be recorded from infants? • Hypothesis: PCFR is recordable. • (2) How does infant response compare to adult response? • Hypothesis: Infants will have greater pitch strength to 55dB stimulus • (3) Does the PCFR response get stronger as an infant gets older? • Hypothesis: Infants PCFR response will get stronger an infant gets older.

  8. Methods - Participants • 10 Adults • 7 Infants • Qualifications • Ability to be restful • Normal hearing • Adult: Thresholds normal across all frequencies between 250 and 8000 Hz • Infant: Distortion Product Otoacoustic Emissions - 2000-8000 Hz.

  9. Methods - Stimulus • Voiced Mandarin Chinese syllable • Rising lexical tone: /yi/ meaning ‘aunt’.

  10. Methods- Protocol • One session • Signing consent form • Hearing screening • Electrode/ear tip placement • Restful state achieved • Stimulus and recording started • Two trials of 1200 tokens • Two trials of 1200 control • Clean up and reimbursement forms completed *** Infant_001 completed three session at 1,3,5 months

  11. Methods- Analysis – Q1 • Linear regression between the stimulus and response Fo spectrogram contours was completed to indicate how well the two contours were correlated. • If response was similar to stimulus then we knew it is a PCFR.

  12. Methods- Analysis – Q2 • Autocorrelation – correlating the response to itself • Estimation of pitch period • Estimation of response strength to the pitch (peak to trough amplitude)

  13. Methods – Analysis- Q2 • Analysis of variance (ANOVA) • Compare: • Infant response strength • Adult response strength

  14. Methods – Analysis- Q3 • Plot pitch strength of longitudinal data. • Compare: • Pitch strength • Age in months

More Related