The effect of nearby timpani strokes on horn playing

Horn players have observed that timpani strokes can interfere disruptively with their playing, especially when they are seated close to the timpani. Measuring the horn's transfer function in the bell-to-mouthpiece direction reveals that the horn behaves as an acoustic impedance matching device, capable of transmitting waves with pressure gains of at least 20 dB near horn playing resonances. During moderate to loud timpani strokes, the horn transmits an overall impulse gain response of at least 16 dB from the bell to the mouthpiece, while evidence of non-linear bore propagation can be observed for louder strokes. If the timpani is tuned near a horn resonance, as is usually the case, further bore resonance interactions may be observed leading to gains of ∼26 dB from bell to mouthpiece. Finally, measurements of horn playing made under conditions approximating playing reveal that timpani strokes sounding near the horn bell are capable of disrupting horn playing by affecting the amplitude, periodicity, and frequency of the pressure signal generated at the horn player's lips.