The Birmingham age-herald., 1923-05-20
HERE $ CAUSE 0F PECULIAR SOUND
 IF AUTO HORN
Inventor Worked To Obtain Quality Of Human
 Voice
By H. W. HENRY Chief Engineer, Klaxn, Co.,, Newark,
 N, J,

ny H. w. f1INHX Chief Engineer, Klaxn, Co.,, Newark.
 N. J.
 Probably the most interesting thing about an automobile horn ts it's peculiar sound. There is reason for this peculiar sound. In this fourth of a series of six edu- cational articles on the automobile horn, this subject Is discussed. Editor.
 ARTICLE "
 Why The Peculiar Sound Of The Au-
 tomobile Horn.
 The note of a genuinely good au- tomobile horn Is a note of warning dominating, penetrating, command ing attention. It is not made to be pleasant to the ear. It Is not Swan Song. It should at once express, and be nstinctively understood, as standing for danger.
 Dr. Miller Reese Hutchinson scientist inventor and originator of the klaxon horn, worked on the theory that an automobile horn should contain something of the quality of an animal sound or human voice sound, in danger. When in distress or danger, an animal or even human being. gives out ter rifying sound.
 An animals shriek In the night or 
 ger is terrifying sound. Hudson Maxim. the inventor. verified the theory held by Dr. Hutchinson by making a study of monkeys, lions and tigers, and noting the various sounds made by them when pleased or angered or terrified. There was kind of common quality to these sounds to denote various moods.
 It is an interesting fact that the peculiar low growl of our own horn Is called around the factory the tiger" reminiscent of the origin of the horns sound.
 Every kind of tone has been tried to obtain for an automobile horn quality of sound that will startle- that will command attention-that will cut through all other noises and will be needed instantly.
 The sound must not only command but must dominate all other sounds. The sound must be free of distract Ing overtones. Overtones prevent penetration. A sound with overtones is merged or lost in other sounds
 The usual horn sound Is produc- ed by the rapid vibration of a thin metallic disc or diaphragg. The vibration creates sound waves In the aid-sound waves which are concen- trated and directed by a horn-shap- ed protector attached to a collar in front of the diaphragm. A protector amplifies and projects the sound. If the vibrating diaphragm or metallic disc did not have column of air resting on it through the projector, a metallic sound would be given off instead of the resonant noise.
 Now a diaphragm, like a pendu- lum yibrates freely at a certain, de- finite fixed natural period of vibra- tion or Frequency. Use Is made of this phenomenon in our horns, for instance, by having the speed of the electric motor. which revolves the motor, adjusted to the diaphragm vibrator. The effect of this phenom enon is so pronounced that, within certain limits, the diaphragm Vibra- tions practically control the motor speed. ..
 This subject of sound quality as 1t applies to the horn Is one of the most interesting in the automobile industry. Thousands of dollars are being spent yearly in research work along this line.
 This subject of sound quality as 1t applies to the horn Is one of the most interesting in the automobile industry. Thousands of dollars are being spent yearly in research work along this line.
 The future development of the au- tomobile horn will be taken up In the next article.