AUDIBLE FREQUENCY RANGES 623 



define the ranges of noise. In some cases noise and tone seemed in- 

 separably blended. 



The qualitative observations made by the observers are summarized 

 in the notes below, in which "L. F. " means "lowest fundamentals." 



Tympani — Xo important frequencies below 65 cycles (drum tuned to 96 cycles). 



Actual tone range ends around 2000 cycles. Prominent drum rattle and beating 



noises to around 5000 cycles. 

 Bass Drum — Xo important frequencies below 70 cycles. Actual tone range ends 



around 1000 cycles. Prominent drum rattle and beating noises to around 



5000 cycles. 

 Snare Drum — -Xo important frequencies below 100 cycles. Actual tone consists of 



rattle extending to very high frequencies. 

 14" Cymbals — Xo important frequencies below 350 cycles. Low frequencies prom- 

 inent when one cymbal is struck with a hard stick. High frequencies prominent 



when two cymbals are clashed together. 

 Bass Viol — L. F. fairly important, slightly more on plucked than on bowed notes. 



Considerable bowing noise. 

 Cello — L. F. fairly important. Tone very rich in harmonics. Moderate bowing 



noise. 

 Piano — L. F. unimportant for first octave. 100 cycle high pass filter only slightly 



noticeable. Upper notes practically pure tones. 

 Violin — L. F. important. Tone rich in harmonics. Noises and tone blended. 

 Bass Tuba — L. F. fairly important. "Pedal" notes — fundamentals around 20 



cycles — contain fewer very low frequencies than regular notes. Moderate blow- 

 ing and key noises. 

 Trombone — L. F. not very important below 130 cycles. Middle register has greatest 



harmonic content. Inappreciable noise. 

 French Horn — L. F. unimportant below 130 cycles. Middle register has most volume 



and harmonics. High register gives rather pure tones. Harmonics least prom- 

 inent of any instrument tested. 

 Trumpet — L. F. fairly important. Lowest register has greatest high frequency 



"blatt." Tones purer at higher pitches. Inappreciable noise. 

 Bass Saxophone — L. F. not very important below 90 cycles. Highest register rather 



unmusical and unpleasant. Considerable blowing and key noise. 

 Bassoon — L. F. fairly important. Prominent reed noise on lower register. Moderate 



key slap. 

 Bass Clarinet — L. F. very important. Tone goes to very high frequencies on upper 



register. Prominent reed noise on lower register becoming blended with tone on 



upper register. 

 Clarinet — ^L. F. very important. Medium range has largest harmonic content. 



Highest range gives much purer tones. Moderate blowing and reed noises at 



very high frequencies. 

 Soprano Saxophone — L. F. very important. Powerful harmonics making very harsh 



tone. Moderate reed noise above 10,000 cycles, less than that of clarinets. 

 Oboe — L. F. important. Most "reedy" tone of all tested. Tone extremely rich in 



harmonics of high order, especially middle register. Noises blended with tone. 

 Flute — L. F. very important. Middle register has most harmonics. Highest register 



produces almost pure tones. Much blowing and mechanism noise on highest 



register. 

 Piccolo — L. F. very important. Middle range most musical and free from noise. 



Highest few notes are very powerful but are practically pure tones. Much blow- 

 ing noise and rumble on all registers. 

 Footsteps — Xo important frequencies below 100 cycles. High frequencies up to 



about 10,000 or 12,000 cycles required. 

 Handclapping — Xo important frequencies below 150 cycles, but requires the entire 



audible range on the high frequency end. Sounds fairly natural with 8500 cycle 



cut-off. 

 Key jingling — bunch of 22 keys shaken on 4" wire loop — -Xo important frequencies 



below 500 cycles but requires entire audible range on the high frequency end. 



Tone very unnatural with 8500 cycle cut-ofT. 



