But even here we cannot stop. To imitate the singer actually is one thing; mental imitation is something entirely different. In the first case, actual imitation, our muscular sense would inform us of the state of throat tightening. But in the case of mental imitation there is no actual tightening of the throat, nothing, at any rate, comparable to what takes place in actual imitation. There is then a dual function of the imagination; first, the mental imitation of the sound; second, the imaginary tightening of the throat. The analysis of the mental process must therefore be modified, and stated as follows: When we listen to a throaty tone we mentally imitate the tone; an imaginative function of the muscular sense informs us what condition the singer's throat assumes for the production of the tone.
A similar operation takes place in listening to nasal voices. An impression is conveyed by a nasal tone, through which the hearer is informed of a condition of tightness or contraction somewhere in the singer's nose.
The terms applied to the two most marked forms of faulty tone-production, nasal and throaty, are derived from impressions conveyed by the sounds of the tones. These names, nasal and throaty, refer to a feeling of tightness or contraction experienced in imagination by the hearer; in one case this feeling is located in the nose, in the other, in the throat. But the terms nasal and throaty are general descriptions of faulty tones. Each one covers a wide range of tone qualities. There is an almost infinite variety of throaty tones, and of nasal sounds as well. The knowledge of the voice obtained by listening to vocal tones is of equally wide extent. Every throaty tone, whatever its precise character, informs the hearer of the exact condition of the singer's throat in producing the tone. In short, every vocal tone is thus analyzed by the critical listener, and referred in imagination to his own throat. An insight into the singer's vocal action is imparted to the hearer through an imaginative process which always, of necessity, accompanies the attentive listening to vocal tones.
Every vocal tone awakens in the hearer a set of imagined muscular sensations. These sensations furnish the means for an exhaustive analysis of the operations of the voice. The production of tone therefore awakens two sets of muscular sensations, one actually felt by the singer, the other felt in imagination by the listener. The former are commonly known as the "singer's sensations"; but, as will be explained later, this expression is often very loosely applied. It is advisable on this account to give a new name to the singer's sensations, and also to give a name to the muscular sensations awakened in the hearer. Let us therefore call the sensations experienced by the singer in the production of tone the "direct sensations of tone." To the imaginary sensations of the hearer let us give the name, the "sympathetic sensations of tone."
These two terms will be used throughout the remainder of this work in the meanings here given to them.
Direct sensations of tone are the sensations actually felt by the singer as a result of the exercise of the vocal organs.
Sympathetic sensations of tone are the muscular sensations experienced in imagination by the hearer as a result of the listening to the tones of voices other than his own.