Sensory Evaluation Testing of Trumpets and Correlation with Acoustic Measurements
Matthias Bertsch, Karin Waldherr, Wilfried Kausel · 2005
The quality and playability of trumpets depends on several parameters. The aim of the trumpet research project in Vienna (www.bias.at/TRP) was to find objective criteria for brass instruments in sensory evaluation playing tests and their bridging with physical measurements. Therefore more than 250 playing tests have been performed by 55 international, mostly professional trumpet players, and terms describing trumpet response have been correlated with measured physical characteristics of those instruments. To rule out terms inconsistently used by players, repeatability of judgments was investigated using a blind test approach. Interestingly, such commonly used terms like response, resistance or certain tone colours turned out to be completely inconsistent. Fortunately some of the more reliable terms seem to actually describe aspects related to trumpet response (detailed results have been published at this year's AAAA conference in Opatija). In the present paper correlation results between the terms “promptness of feedback”, “repetition rate”, “lip up/down capability”, “dynamic range mid register”, “brilliance”, “output power” and “overall quality”, and certain features of the measured input impedance curve of the instruments are discussed. The input impedance curves have been measured using the BIAS system, software release 6.0, which provides additional features extracted from the measured data. From the input impedance magnitude curves size, 3dB bandwidth and radius of curvature are extracted for each played resonance. The impedance phase curves are investigated for remaining phase and group delay at the peak centre frequencies as well as for the distance of the closest phase zero.