Investigating oboe manufacturing consistency by comparing the acoustical properties of five nominally identical instruments

For large-scale musical instrument makers, the ability to produce instruments with exactly the same playing characteristics is a constant aim. Modern acoustical measurement techniques (such as acoustic pulse reflectometry and input impedance measurement methods) together with psychoacoustical testing, can help this goal be reached. This paper investigates the issue of instrument manufacturing consistency by comparing the acoustical properties and the perceptual qualities of five Howarth S10 student oboes. Input impedance measurements have been made on the five oboes for fingerings throughout the standard playing range of the instrument, acoustic pulse reflectometry has been used to measure the bore profiles of the oboes, and nine musicians have taken part in a two-alternative-forced-choice discrimination playing test using two of the instruments. The main findings are (i) the instruments are perceived as identical by most of the musicians tested, (ii) a variation in the playability of the note F6 experienced by two of the musicians is shown to be due to differences in the elevation of the pad above the C hole, and (iii) some small variations in the playing properties in the first register of the instruments are shown to be related to differences in input impedance which, in turn, appear to arise from small differences in the bore profiles of the instruments