Does phonetics's definition of 'voiceless' differ from the absence of voice?

Question

Preface: For differentiation, henceforth 'voiceless' means the phonetic definition;
I define elinguis to mean a layperson's understanding of an absence of human voice or speech.

Source: p 27, The Study of Language (5 ed, 2014) by George Yule

Inside the larynx are your vocal folds (or vocal cords), which take two basic positions.

1 When the vocal folds are spread apart, the air from the lungs passes between them
unimpeded. Sounds produced in this way are described as voiceless.

2 When the vocal folds are drawn together, the air from the lungs repeatedly pushes them apart as it passes through, creating a vibration effect. Sounds produced in this way are described as voiced.

The distinction can be felt physically if you place a fingertip gently on the top of your Adam’s apple (i.e. that part of your larynx you can feel in your neck below your chin), then produce sounds such as Z-Z-Z-Z or V-V-V-V. Because these are voiced sounds, you should be able to feel some vibration. Keeping your fingertip in the same position, now make the sounds S-S-S-S or F-F-F-F. Because these are voiceless sounds, there should be no vibration. Another trick is to put a finger in each ear, not too far, and produce the voiced sounds (e.g. Z-Z-Z-Z) to hear and feel some vibration, whereas no vibration will be heard or felt if you make voiceless sounds (e.g. S-S-S-S) in the same way.

To a layperson, the term 'voiceless' seems counterintuitive because humans can still detect, hear, and listen to voiceless sounds (eg: whispering); to wit, voicelessness = elinguis.
1. So to a linguist, is 'voiceless' NOT 0% sound or voice? To wit, voicelessness ≠ elinguis?
2. If the answer to 1 is affirmative, then why was 'voiceless' selected so carelessly?
Surely this confusing polysemy of 'voiceless' could have been anticipated?

Answer 1

I think the problem here is that you equate elinguis and voicelessness as both meaning without sound/inaudible. But voice is a technical term that does not actually refer to the audible sound of speech generally, as suggested by sayings such as "lose one's voice" or "to have a (nice) voice", both of which refer to the quality or existence of a person's speech. Instead the term voice as a technical term refers to vibration of the vocal folds, and voicing can refer to either the existence of vocal fold vibration or the typology of different types of voice, such as voicelessness, modal voice, creaky voice (think "vocal fry"), etc. Phoneticians, and linguists more generally, understand voice as that technical term, rather than as general term for the sound of speech, which linguists aptly refer to as speech or the speech signal.

The "0% sound" you indicate is what you acoustically get from voiceless stop consonants, such as the sound [p]. If you say "apart" very slowly, you will hear that there is no audible sound at all in the middle portion of the [p]. In comparison, in "abrupt" you can still hear a low frequency buzz during the [b], at least for a little while until the pressure differential across the vocal folds has equalised. So it is true that phonetic voicelessness is usually needed for silence, but it is false that phonetic voicelessness necessitates silence, e.g. the sound [S] in "assure" does not have phonetic voicing but is audible nonetheless.

As to the question why voice became a technical term despite potential for confusion, it's no different from most technical terminology really. When people need to describe something new in a very precise way, they often take a more general term that already refers to something related (voicing is implicated in pitch, and hence especially linked to the idea of voice in singing vocalisation) and define that term more narrowly. As long as the term is not already a technical term in the same domain, and all the other people who work in that domain know about the term's specific meaning, there's no problem. Language is full of homophony, and you don't usually get confused by it--even with puns we are extremely good at telling the literal meaning apart from the alternative, simply by using the context it appears in.

Answer 2

Please notice that Yule's definition is not entirely coherent. If there are two basic positions of the vocal cords, and one of them is when the vocal cords are spread sufficiently to prevent vibration of the vocal cords, the other possibility is that the vocal cords are not spread sufficiently to prevent vibration.

But the problem here is that just because the cords are not spread enough to prevent vibration, it doesn't follow that that there will be vibration. It can happen that vibration is prevented by the vocal cords being clamped tight together, as they are for glottalized consonants. Clearly in that case the cords are not spread, so if vibration is prevented by closing the vocal cords, this ought to count as voiced, even though there is no vibration.

As I read the account in The Sound Pattern of English, glottal stop and glottalized consonants do count as voiced, even though there is none of the buzzing that an intuitive account of voicing might suggest.

I'm not against this, but it can be confusing to the unwary.