Are Classical Tibetan "syllables" actually one syllable, like we think of English syllables?

Question

Words like /bkroŋs/ and /bsgrubs/ are called "syllables" in Tibetan. Yet, there is no way to pronounce a "b" and a "k" in a sequence, without a syllabic pause between them. It is physically impossible it feels like. The "b" is lips opening to air, and "k" is throat opening to air. You can't open your lips and open your throat in the same flow, in slow-motion you are doing:

b ... kroŋs

It is as if you are saying /bʊkroŋs/, or even so far as just /b.kroŋs/, all of which are two syllables. The "b" must come before the "k", and is a syllable edge.

Are Tibetan syllables really not syllables like you would find in English, but are some other structures which begin with a consonant (or cluster) and end with an optional consonant (or cluster), and that's it? Or are they somehow blending these two sounds together which seem to be physically impossible?

Answer 1

Wikipedia explains how the Old Tibetan syllable structure worked (emphasis added):

In Old Tibetan, syllables can be quite complex with up to three consonants in the onset, two glides, and two coda consonants. This structure can be represented as (C1C2)C3(G1G2)V(C4C5), with all positions except C3 and V optional. This allows for complicated syllables like བསྒྲིགས bsgrigs "arranged" and འདྲྭ 'drwa "web", for which the pronunciations [βzɡriks] and [ɣdrʷa] can be reconstructed.

A voicing contrast only exists in slot C3 and spreads to C1 and C2 so སྒོ sgo "door" would be realized as [zɡo] while སྐུ sku "body" would be [sku]. Final consonants are always voiceless e.g. འཛིནད་ 'dzind [ɣd͡zint] and གཟུགས་ gzugs [gzuks]. The phoneme /b/ in C1 was likely realized as [ɸ] (or [β] when C3 is voiced) e.g. བསྒྲེ bsgre [βzɡre] and བརྩིས brtsis [ɸrtˢis]. The features of palatalization /i̯/ [Cʲ] and labialization /w/ [Cʷ] can be considered separate phonemes, realized as glides in G1 and G2 respectively.

Modern Tibetan phonology has no consonant clusters. From a Reddit post I infer that there are a lot of silent letters in modern Tibetan, such that those initial "b"s are no longer spoken at all, at least in some words.

Answer 2

I too am looking forward to someone knowledgeable to answer this long-standing question of mine. Until such time, I have to offer a few clues to open your mind a bit as far as the concept of a syllable is concerned:

• Observe there are languages with stops that release at two points of obstruction simultaneously, and you can easily do that yourself
• the prefix in bk- could be symbolic, indicating a sound that has commonalities with [b] but is not precisely [b]
• the prefixes could act similarly to French mute coda consonants that only surface under special conditions (see 'liaison')
• syllables are not necessarily integer, they may also be 'fractional'. Ex. when you model syllable boundaries using a segmental symbol like [#], how do you model En. folly—is it /fo#li/ or /fol#i/? A third possibility cannot be modeled by the boundary-as-segment model, namely that the /l/ belongs to both the first and the second syllables (it is ambisyllabic). Likewise, when you compare 'blue' with 'bluer', it is certainly possible to say the latter in two distinct syllables, but when you utter 'a blue life' and 'a bluer life', the latter one certainly has 'less syllables' than, say, 'a blue-green life', indicating that the '-er' is a fraction of a syllable.
• I can totally say [bkro-] without a vowel between [b] and [k] by filling my closed mouth with air while the glottis produces the voicing, then do a dorso-velar release, followed by a tongue gesture for the rhotaid. Observe that in e.g. German 'Herbst' we have a syllable ending in [-rpst] that are likewise uttered in sequence without intervening vowels that constitute a single syllable coda.