Should convert 'k' and 't' sounds to 'g' and 'd' sounds when they follow 's' in a word for pronunciation?

Question

Should convert 'k' and 't' sounds to 'g' and 'd' sounds when they follow 's' in a word for pronunciation?

For example, stamp is pronounced as 's dæm p', etc.

Answer 1

No. You should pronounce it as an unaspirated [t].

Longer: There are two phenomena in play: aspiration and voice.

sounds	voiced?	aspirated?
/p t k/	no	at the start of a syllable
/b d g/	yes	no

Thus what you hear in a cluster like 'stamp' is the voiceless plosive /t/ without its aspiration. Its voicing does not change.

However, because many languages, probably incl. yours, do not use aspiration, English's use of it is very salient. Thus it's easy to mistake it for the quality that defines /p t k/.

But it isn't. It's secondary from the phonological point of view. The phoneme /t/ has phonetic realizations [t] and [tʰ] (among others); it does not have a phonetic realization [d]. Hence, it's [stæmp], but not [stʰæmp] and not [sdæmp].

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Incidentally, English native speakers have a similar problem. Take away the aspiration and we think we're perceiving /b d g/. However, it's possible to train yourself to perceive the distinction.

Hence, it might be possible to argue that aspiration is the key element and voicing is the second. But even if aspiration is treated as the primary distinction, it doesn't really make sense to target a /d/. A /d/ should be impossible in a cluster after a voiceless /s/ from a phonotactics point of view.

Answer 2

Yes, in fact. English speakers cannot tell the difference between "stamp" and "sdamp" (or "disgust" and "discussed", etc.) in most speech, no matter how much they tell you they can. It's possible to pronounce them so they can be distinguished, but this is not the same thing as doing so by default.

Linguist Geoff Lindsey demonstrates here that clipping the /s/ out of an audio clip of the word "speech" makes it indistinguishable from "beach".

Answer 3

It depends. To what accent do you, er, aspire?

Native English speakers from, say, India readily distinguish /p t k/ from /b d g/ in all positions of those consonants—even after f or s. That's due to the influence of Indic languages, where aspiration is phonemic. /p/ and /p^h/ are meaningfully different: e.g., in Hindi, pal, पल, moment; phal, फल, fruit. Indeed, /ph/ is not phonemically distinct from /f/ in those languages. The following relations pertain:

pronunciation	Indian listener	American listener
[p]	/p/	/b/
[ph]	/f/	/p/

All this can make things a bit bewildering, as when the Indian speaker says "I gave the dog a pat" and the American listener wonders why the speaker gave the canine a flying rodent 🦇. Or when an American speaker says "You deserve some pats on the back" and the Indian listener ponders dorsal applications of butter, margarine, olive oil, etc.

To somebody from India, then, even after an s, /p/ is pronounced [p]. Or more precisely, it's pronounced the same way as /p/ is pronounced at the initial position of a morpheme. And that pronunciation is very distinct from [b] to an Indian ear, but not so much to an American one.

Dr Lindsey's video, referenced in @the-baby-is-you's answer, furnishes a case in point. For each pair of words (door/store, speech/beach) there is at least one speaker whose pronunciation does distinguish the pair clearly enough for my Indian ear. In general, though, he is obviously correct: US/UK pronunciations do not distinguish between /p/ and /b/ (etc.) following s or f. However, while Dr Lindsey conflates "native speaker" with "British or American", there are large numbers of native speakers of English elsewhere in the world. And I do mean native, those who grew up speaking the language either exclusively or in true bilingual/multilingual fashion, as opposed learning it as a second, third, or fourth language outside of an immersive context.

So if your native language isn't English, then does your native language give you the ability to hear and reproduce the distinction between [p], [p^h], and [b]? If so, and if you don't mind having an accent that's somewhat distinctive, by all means reproduce those distinctions. If you cannot consistently hear or reproduce those distinctions, then by all means follow the advice to say "sbeach" or "sgool" for "speech" or "school".

At the end of the day, though, the point is to recognize that even native accents are bewilderingly various. Arguing over whether [p], [p^h], and [b] are, or ought to be, distinct is about as fruitful as arguing whether Mary, marry, and merry are pronounced identically or entirely differently. It all depends: where are you from; how conscious are you of your own accent; to whom are you speaking; and how much do you care that your accent seem neutral to them?

Answer 4

Pinyin g and d are English unaspirated k and t.

one can put a hand or a lit candle in front of one's mouth, and say spin [spɪn] and then pin [pʰɪn]. One should either feel a puff of air or see a flicker of the candle flame with pin that one does not get with spin.

In English, stop is [stɑp], top is [tʰɑp], but day is [deɪ̯].

Pinyin d is [t], pinyin t is [tʰ], so dao is [taʊ] and tao is [tʰaʊ].

stamp should be pronounced as [stæmp] with an unaspirated t. That's not the same as English d (which normally represents IPA [d]).

The English d sound does not exist in Mandarin as far as I know. It is a voiced consonant, in English the vocal folds begin to vibrate before the consonant is released (voice-onset time).

In English, the stops p, k, and t are aspirated when they are at the start of a syllable, but not otherwise.

For example, port would be [pʰɔɹt], passport would still have aspiration [pʰæs.pʰɔɹt], but sport should be [spɔɹt] without aspiration.

So, you should only pronounce /t/ as [tʰ] if it is at the start of a syllable. It doesn't matter if it follows an s or not.

Answer 5

Should convert 'k' and 't' sounds to 'g' and 'd' sounds when they follow 's' in a word for pronunciation?

For example, stamp is pronounced as 's dæm p', etc.

How to answer this question depends on the context.

It's definitely true that the words stamp and skin are not pronounced with the same sounds that the letters T and K make in the words tank and kin. You are right to notice this.

You can use websites like Forvo and Youglish to hear how English speakers pronounce words like "stamp" (Forvo) ("stamp" Youglish) and "skin" (Forvo) ("skin" Youglish).

Imitating this as best as you can should result in an understandable pronunciation.

Why you hear a difference, and what that difference is

The phonetic difference is that words like tank and kin have a puff of air, called "aspiration", at the end of their T and K sounds, while "stamp" and "skin" do not.

This difference isn't represented in English spelling because English words can't start with an S sound followed by an aspirated T or K sound.

It's the same as the difference in Standard Chinese/Mandarin between the sounds written in pinyin with the letters t p k (which are aspirated) and the sounds written in pinyin with the letters d b g (which are not aspirated). So if you are familiar with that, and that's what you mean by writing 's dæm p', then that's a correct description of the start of English "stamp": the voiceless fricative S followed by an unaspirated voiceless consonant.

However, the letter d isn't generally used to represent an unaspirated voiceless consonant in the International Phonetic Alphabet. Instead, in this alphabet, we would mark the difference by transcribing "tank" and "kin" with [tʰ] and [kʰ], where the [ʰ] symbol represents the aspiration of the consonant, vs. "stamp" and "skin" with [st] and [sk] (with no [ʰ]).

The International Phonetic Alphabet prescribes using the letters [b d ɡ] to transcribe what are called "voiced" consonant sounds. These don't appear after word-initial [s] in English, but because they are also unaspirated, some English speakers hear a similarity between them and the voiceless unaspirated [p t k] sounds, as described by the-baby-is-you's answer. (The English phonemes transcribed /b d ɡ/ are not always fully phonetically voiced.) Other English speakers, or speakers of some other languages, may not hear this similarity, meaning for those people, it won't make sense to think of words like stamp, skin, spin as starting with sd-, sg-, sb- sounds. That's OK: while you can think of these words as starting with sd-, sd-, sb- if it helps you avoid using the aspirated consonant sounds found at the start of "tank", "kin", "pin", there's no requirement for everybody to think of them this way.

And of course, nobody should get the idea that they should pronounce these words with a phonetically voiced [b d ɡ] sound, so for speakers of languages where those sounds contrast with voiceless unaspirated [p t k], such as Italian, it makes the most sense to think of the English consonant clusters as being like their native [sp] [st] [sk].

Answer 6

P, T, and K aspirations are blocked by certain preceding sounds. See this video https://www.youtube.com/watch?v=U37hX8NPgjQ for how the sounds change and native English speakers don't even know what sounds we're actually making when speaking.