An investigation of correlations between geometry, acoustic variables, and psychoacoustic parameters for French horn mouthpieces
George R. Plitnik, Bruce A. Lawson · The Journal of the Acoustical Society of America · 1999
Because brass instrument mouthpieces are considered by musicians to be the single most important component of the instrument, a comparative investigation was made of seven French horn mouthpieces widely used by professional musicians. Acoustic parameters were obtained from both measured and computed impedance curves for the mouthpieces attached to a cylindrical tube with an overall length approximating that of the horn in B-flat. Hypothesized psychoacoustic correlates to these parameters were used by professional musicians to evaluate the mouthpieces by means of comparative testing. It was discovered that the peak amplitudes and Q values of the impedance peaks, as well as their respective variability, correlated well to the musicians’ preference ratings. Based on the presented documented changes in the ratio of French horn mouthpiece cup length to throat plus backbore length throughout the twentieth century, the acoustical properties of modern designs to the older versions are compared. These results show that the average harmonics’ peak amplitude has increased, while variability has simultaneously decreased, resulting in a more even envelope. Also, the impedance peak’s average Q’s have increased, a probable explanation for musicians’ expressed preference for mouthpieces which facilitate greater pitch control.