title: Cricothyroid muscle and thyroarytenoid muscle dominance in vocal register control: preliminary results.
abstract: OBJECTIVE
  Headmix and head registers use cricothyroid (CT) muscle dominant voicing, whereas chest and chestmix registers use thyroarytenoid (TA) muscle dominant voicing.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  CT and TA electromyographic data obtained from five untrained singers and two trained singers were analyzed to determine CT and TA muscle dominance as a function of register. Simultaneous recordings of TA and CT muscle activity and audio were obtained during production of pitch glides and a variety of midrange and upper pitches in chest, chestmix, headmix, and head registers.
  
  
  RESULTS
  TA dominant phonation was only observed for chest productions and headmix/head register productions below 300 Hz. All phonation above 300 Hz, regardless of register, showed CT:TA muscle activity ratios that were CT dominant or close to 1, indicating nearly equal CT and TA muscle activity. This was true for all subjects on all vocal tasks. For the subjects sampled in this study, pitch level appeared to have a greater effect on TA and CT muscle dominance than vocal register.
  
  
  CONCLUSIONS
  Preliminary findings regarding CT and TA dominance and register control do not support the assumption that all chest and chestmix production has greater TA muscle activity than CT muscle activity or that all headmix and head production require greater CT muscle activity than TA muscle activity. The data indicate that pitch level may play a greater role in determining TA and CT dominance than register.
authors.affiliation: Department of Communication Disorders and Sciences, California State University, Northridge, California. Electronic address: karen.kochis-jennings.32@csun.edu.
authors.forename: Karen Ann
authors.initials: KA
authors.lastname: Kochis-Jennings
authors.affiliation: Department of Communication Sciences and Disorders, University of Iowa, Iowa City, Iowa; Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, Iowa.
authors.forename: Eileen M
authors.initials: EM
authors.lastname: Finnegan
authors.affiliation: Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, Iowa.
authors.forename: Henry T
authors.initials: HT
authors.lastname: Hoffman
authors.affiliation: Department of Hearing, Speech and Language Sciences, Gaulladet University, Washington, District of Columbia.
authors.forename: Sanyukta
authors.initials: S
authors.lastname: Jaiswal
authors.affiliation: Department of Communication Sciences and Disorders, University of Iowa, Iowa City, Iowa.
authors.forename: Darcey
authors.initials: D
authors.lastname: Hull
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004576:Electromyography; D005260:Female; D006801:Humans; D007821:Laryngeal Muscles / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010699:Phonation / Q000502:physiology*; D063346:Singing / Q000502:physiology*; D014827:Vocal Cords / Q000502:physiology*; D014831:Voice / Q000502:physiology*; D055815:Young Adult
keywords: Cricothyroid muscle; EMG; Thyroarytenoid muscle; Vocal registers