DEEP THOUGHTS  DEEP THOUGHTS

Background

To go on to the theoretical information.

Basics on Sound

These are just a few basic facts about sound behavior that will be used later in my data and error analysis. Sound is a longitudinal wave, but it can be shown as a lateral wave. This is accomplished by taking the harmonic spectrum, or a graph showing the strength of each of each harmonic, and adding together the waves that each harmonic will in itself produce when set in a displacement-time graph. Each of the components will, in itself, produce a sine wave when set in this format, but when added together will produce differant periodic waves.

Basics on Brass Sound Production

Brass instruments are "lip reed" wind instruments. That is they produce their sound by the lips being placed against the end of the open pipe that makes up the horn and vibrating. The fact that the lips are against an open end of the pipe will make the pipe behave as a closed pipe. However, most brass instruments are conical, and will therefore behave harmonically as an open pipe.

The mouth and throat have effect on the tone that is generated by the instrument, even though it does not make sense at the first if you think of the lungs and throat only as wind producers to make the lips vibrate. However, if you think of the lung-throat-mout system as a "second 'brass instrument', with the air flowing in the 'wrong' direction" (Campbell and Greated 325) then you can begin to see how the waves might begin to interfere with each other, creating non-harmonic tones or even canceling each other out.

How We Perceive Sound

This description will be basic simply because, although it is important for this paper, all of the biological information is not necessary to understanding this paper. We perceive sound because of vibrations in the inner ear. Pitch and timbre can be assigned by the ear-brain system through the displacement of the basilar membrane located inside the cochlea. We assign pitches to certain tones by hearing the relationships between the different overtones and assigning the difference between their frequencies as the root. For example, a complex tone with a root of 100 Hz will have overtones at 200, 300, 400, and 500 Hz. Our ear-brain system recognizes this as being at 100 Hz. However we will still "hear" the root at 100 Hz even if a sound is electronically produced that only contains tones at 300 Hz, 400 Hz, and 500 Hz. If one of these overtones is slightly mistuned, say the 4th overtone is playing at 405 Hz rather than 400, our ear-brain system will still determine the root to be at 100 Hz, but the pitch will sound fuzzy or hazy. This is what I'm proposing is happening in a sound that has poor tone quality. The harmonics are mistuned, thus our ear-brain system is having trouble placing the pitch and it sounds poor as a result.

Theoretical Information

To go back to the background information.

Timbre is just another name for tone color. However, consider just how many concepts are encompassed in timbre. An oboe sounds different than a flute, but a beginning flute player sounds thin and airy compared to a seasoned veteran that has been playing professionally for a couple of decades.

Timbre actually begins to encompass all three stages of a sound, those being:
  1. Attack, or the way a pitch begins.
  2. The held or sustained portion of the pitch,
  3. Decay, or the way that a pitch ends.
In actuality what I tested can more precisely be termed "tone quality" as opposed to timbre, as I am not interested so much in what makes a bad sounding trumpet sound different than a bad sounding trombone, but rather what makes a single sound that is the same as another in pitch, volume, and duration, played on the same instrument and the same person different from another sound that simply is different somehow.

Regardless of what it is termed, however, I was unable to find any answer to my two predominant questions in any books that I searched. Thus my own extrapolation will be found in the two following hypothetical sub-works that will begin to explore my questions.