Cortical sensitivity to periodicity of speech sounds.

Previous non-invasive brain research has reported auditory cortical sensitivity to periodicity as reflected by larger and more anterior responses to periodic than to aperiodic vowels. The current study investigated whether there is a lower fundamental frequency (F0) limit for this effect. Auditory evoked fields (AEFs) elicited by natural-sounding 400 ms periodic and aperiodic vowel stimuli were measured with magnetoencephalography. Vowel F0 ranged from normal male speech (113 Hz) to exceptionally low values (9 Hz). Both the auditory N1m and sustained fields were larger in amplitude for periodic than for aperiodic vowels. The AEF sources for periodic vowels were also anterior to those for the aperiodic vowels. Importantly, the AEF amplitudes and locations were unaffected by the F0 decrement of the periodic vowels. However, the N1m latency increased monotonically as F0 was decreased down to 19 Hz, below which this trend broke down. Also, a cascade of transient N1m-like responses was observed in the lowest F0 condition. Thus, the auditory system seems capable of extracting the periodicity even from very low F0 vowels. The behavior of the N1m latency and the emergence of a response cascade at very low F0 values may reflect the lower limit of pitch perception.

[1]  P. Alku,et al.  A method for generating natural-sounding speech stimuli for cognitive brain research , 1999, Clinical Neurophysiology.

[2]  R. Patterson,et al.  The lower limit of melodic pitch. , 2001, The Journal of the Acoustical Society of America.

[3]  R. Hari,et al.  Auditory evoked transient and sustained magnetic fields of the human brain localization of neural generators , 1980, Experimental Brain Research.

[4]  Werner Lutzenberger,et al.  MEG responses to rippled noise and Huggins pitch reveal similar cortical representations , 2005, Neuroreport.

[5]  J A Bashford,et al.  Perception of acoustic iterance: Pitch and infrapitch , 1981, Perception & psychophysics.

[6]  H. Davis,et al.  Effects of duration and rise time of tone bursts on evoked V potentials. , 1968, The Journal of the Acoustical Society of America.

[7]  Paavo Alku,et al.  An amplitude quotient based method to analyze changes in the shape of the glottal pulse in the regulation of vocal intensity. , 2006, The Journal of the Acoustical Society of America.

[8]  M Hoke,et al.  The auditory evoked sustained field: origin and frequency dependence. , 1994, Electroencephalography and clinical neurophysiology.

[9]  Yoshiharu Soeta,et al.  Auditory evoked magnetic fields in relation to iterated rippled noise , 2005, Hearing Research.

[10]  R. Patterson,et al.  Evidence of pitch processing in the N100m component of the auditory evoked field , 2006, Hearing Research.

[11]  T. Picton,et al.  Human auditory sustained potentials. II. Stimulus relationships. , 1978, Electroencephalography and clinical neurophysiology.

[12]  Brian R Glasberg,et al.  Derivation of auditory filter shapes from notched-noise data , 1990, Hearing Research.

[13]  David Poeppel,et al.  Neural response correlates of detection of monaurally and binaurally created pitches in humans. , 2006, Cerebral cortex.

[14]  B Lütkenhöner,et al.  Neuromagnetic evidence for a pitch processing center in Heschl's gyrus. , 2003, Cerebral cortex.

[15]  C Pantev,et al.  Magnetic and electric brain activity evoked by the processing of tone and vowel stimuli , 1995, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[16]  R. Zatorre,et al.  Voice-selective areas in human auditory cortex , 2000, Nature.

[17]  B. Delgutte,et al.  Neural correlates of the pitch of complex tones. I. Pitch and pitch salience. , 1996, Journal of neurophysiology.

[18]  Bela Julesz,et al.  Lower Limits of Auditory Periodicity Analysis , 1963 .

[19]  Bernd Lütkenhöner,et al.  Piano tones evoke stronger magnetic fields than pure tones or noise, both in musicians and non-musicians , 2006, NeuroImage.

[20]  J. Mäkelä,et al.  Magnetic responses of the human auditory cortex to noise/square wave transitions. , 1988, Electroencephalography and clinical neurophysiology.

[21]  Stefan Uppenkamp,et al.  Temporal dynamics of pitch in human auditory cortex , 2004, NeuroImage.

[22]  Gunnar Fant,et al.  Some problems in voice source analysis , 1993, Speech Commun..

[23]  J. Sundberg,et al.  Spectral correlates of glottal voice source waveform characteristics. , 1989, Journal of speech and hearing research.

[24]  T. Picton,et al.  Human auditory sustained potentials. I. The nature of the response. , 1978, Electroencephalography and clinical neurophysiology.

[25]  T. Picton,et al.  The N1 wave of the human electric and magnetic response to sound: a review and an analysis of the component structure. , 1987, Psychophysiology.

[26]  R Todd Constable,et al.  Differentiation of speech and nonspeech processing within primary auditory cortex. , 2006, The Journal of the Acoustical Society of America.

[27]  R. Patterson,et al.  The lower limit of pitch as determined by rate discrimination. , 2000, The Journal of the Acoustical Society of America.

[28]  Sachiko Koyama,et al.  Magnetoencephalographic study of the cortical activity elicited by human voice , 2003, Neuroscience Letters.

[29]  K Mathiak,et al.  Differential impact of periodic and aperiodic speech‐like acoustic signals on magnetic M50/M100 fields , 2000, Neuroreport.

[30]  R. Ritsma Existence Region of the Tonal Residue. I , 1962 .

[31]  Paavo Alku,et al.  Disentangling the effects of phonation and articulation: Hemispheric asymmetries in the auditory N1m response of the human brain , 2005, BMC Neuroscience.

[32]  K. Palomäki,et al.  The periodic structure of vowel sounds is reflected in human electromagnetic brain responses , 2001, Neuroscience Letters.

[33]  M. Schönwiesner,et al.  Vowel processing evokes a large sustained response anterior to primary auditory cortex , 2006, The European journal of neuroscience.

[34]  J. Mäkelä,et al.  Temporal integration and oscillatory responses of the human auditory cortex revealed by evoked magnetic fields to click trains , 1993, Hearing Research.

[35]  R. Hari,et al.  Responses of the human auditory cortex to vowel onset after fricative consonants , 2004, Experimental Brain Research.

[36]  Roy D. Patterson,et al.  Sustained Magnetic Fields Reveal Separate Sites for Sound Level and Temporal Regularity in Human Auditory Cortex , 2002, NeuroImage.

[37]  T. Elbert,et al.  Cortical representation of vowels reflects acoustic dissimilarity determined by formant frequencies. , 2003, Brain research. Cognitive brain research.