Twitch response in the canine vocalis muscle.

The twitch response of the canine vocalis muscle was investigated through a series of experiments conducted in vitro. Samples of vocalis muscle were dissected and prepared from canine larynges a few minutes before death and kept in Krebs solution at a temperature of 37 +/- 1 degrees C and pH of 7.4 +/- 0.05. Field stimulation with parallel-plate silver electrodes was applied to study the twitch response of muscle samples. The peak tension and time course of isometric contraction of isolated muscle samples were measured electronically with a Cambridge Technology Dual Servo System (ergometer). Contraction time and 50% relaxation time of this muscle were measured for seven samples at various levels of strain. It was found that contraction time ranged between 22 and 32 ms and 50% relaxation time ranged between 17 and 37 ms. Results indicate that the vocalis muscle is a fast muscle capable of performing rapid maneuvers in support of changes in fundamental frequency.

[1]  D. Wilkie,et al.  Muscle Physiology , 1959, Nature.

[2]  Harry Hollien,et al.  Vocal Pitch Variation Related to Changes in Vocal Fold Length , 1960 .

[3]  C. Skoglund,et al.  CONTRACTION PROPERTIES OF INTRINSIC LARYNGEAL MUSCLES. , 1964, Acta physiologica Scandinavica.

[4]  M. Hast.  Mechanical Properties of the Vocal Fold Muscle , 1967 .

[5]  J. Ohala,et al.  The function of laryngeal muscles in regulating fundamental frequency and intensity of phonation. , 1968, Journal of speech and hearing research.

[6]  T. Ushijima.  [Experimental study of the contraction properties of the laryngeal muscles in the cat]. , 1968, Nihon Jibiinkoka Gakkai kaiho.

[7]  P. Rack,et al.  The effects of length and stimulus rate on tension in the isometric cat soleus muscle , 1969, The Journal of physiology.

[8]  J. Ohala,et al.  Regulation of register, pitch and intensity of voice. An electromyographic investigation of intrinsic laryngeal muscles. , 1970, Folia phoniatrica.

[9]  T. Shipp,et al.  Laryngeal dynamics associated with voice frequency change. , 1971, Journal of speech and hearing research.

[10]  S. Niimi,et al.  Control of fundamental frequency, intensity, and register of phonation , 1975 .

[11]  J. Atkinson.  Correlation analysis of the physiological factors controlling fundamental voice frequency. , 1978, The Journal of the Acoustical Society of America.

[12]  R. Close.  Activation delays in frog twitch muscle fibres. , 1981, The Journal of physiology.

[13]  Charles R. Larson.  Voice fundamental frequency changes following discharge of laryngeal motor units: Biomechanics, Acoustics and Phonatory Control , 1983 .

[14]  Elasticity of canine vocal fold tissue. , 1984, Journal of speech and hearing research.

[15]  I. Titze,et al.  Viscoelastic modeling of canine vocalis muscle in relaxation. , 1985, The Journal of the Acoustical Society of America.