HO PART II. SOME IMPORTANT METHODOLOGICAL TERMS. 



of (say) sound sensations as follows, omitting at first fine distinc- 

 tions : 



A. SENSE APPARATUS. I. We connect sound with a spe- 

 cial sense apparatus: the two ears and their afferent continu- 

 ations. 2. However, sounds may, to a marked degree, reach 

 the internal ear directly, as seen in loud breathing with ears 

 closed. 3. We ordinarily hear with both ears. 4. The use of 

 only one ear makes comparatively little difference to the loud- 

 ness and to the quality of the sounds heard. (Compare with 

 monocular vision.) 5. In normal circumstances we cannot tell 

 whether we hear with both ears, except by indirect methods 

 or by trained attention. 6. The ears are so placed that sounds 

 are readily heard from all sides. 7. The ear, unlike the eye, 

 is never closed, presumably because of the need of alertness 

 to danger. 8. The ears can only be closed artificially, and even 

 then sound, when loud, penetrates as a rule to a certain extent. 

 (See also 2.) 9. As implied in 6, sounds, unlike sights, are not 

 readily localised in a direct line with the sense apparatus, though 

 "right" and "left" have a fairly definite meaning to the ears 

 as a* rule (e. g., sharply waving a finger close by the ear to 

 the right and left, above, below, and immediately opposite, 

 sound is only noticeable in the last instance, and then very 

 distinctly). 10. The direction whence sounds emanate can be 

 only imperfectly ascertained through hearing alone, and exact 

 aural localisation in respect of direction and distance is still 

 more difficult (as is evidenced by dogs who are at a loss to 

 trace their unseen master by his voice). (Movements of the 

 head assist to some extent in tracing sound direction.) 11. Cer- 

 tain parts of the external ear and meatus may possibly be more 

 sensitive to auditory vibrations, and thus help to guide in the 

 interpretation of direction, whilst sounds (e.g., occasioned by 

 strong air currents), definitely coming from right or left, more 

 distinctly, affect the correspondingly situated ear. 12. With 

 sounds, unlike with sights, their close proximity to the sense 

 apparatus does not markedly modify them, save in regard to 

 loudness. 13. In intently listening, we cease moving and breath- 

 ing, because of the disturbing noises created in these processes. 

 14. Sound is received with almost complete passivity. 15. Sounds 

 are correspondingly aggressive in their higher reaches. 16. The 

 degree of loudness in a sound, like all intensity in sensations, 

 is not appreciated by the sense of hearing, but by the attention 

 mechanism. 



B. MEDIUM. 1. Sound is distinctly connected with traceable 

 wave media, commonly with the air ; but, as in gently rubbing 

 the temples, a vibration may be directly transmitted to the 

 internal ear. (See A 2 above.) 2. Because of 1, sounds manifest 

 timbre or quality, resulting from the specific form of the vibra- 

 tions; pitch, determined by the frequency of the vibrations; and 

 intensity, caused by the amplitude of the vibrations. 3. Echoes, 



