Dear teachers and members:
Once I asked this same query but it was not well organized as I drew it up this time.
In american English (AmE), in some multisyllable words the /h/ phoneme is silent or elided in isolated words when the previous syllable is stressed; this phonological phenomen also ocurrs in the connected speech. I am not quite sure if this also happens in British English (BrE) too. The following is my exposition about it.
Iº - IN ISOLATED WORDS:
Vehicule /ˈviɪkəl/; 2) Durham /ˈdɜrəm/; 3) Pelham Bay /ˈpɛləm beɪ/; 4) Fordham Road; /ˈfɔrəm roʊd/; the /h/ sound has been elided in all these words.
Pronunciation note in the word VEHICLE.
Because the primary stress in VEHICLE is on the first syllable, the /h/ on the second syllable tends to desapear /ˈviːɪkəl/. A pronunciation with the primary stress on the second syllable and a fully pronounced /h/ is usually considered nonstandard / vɪˈhɪkjʊlər/. In the adjective VEHICULAR, where the primary stress is normal on the second syllable, the /h/ is always pronounced.
IIº - IN CONNECTED SPEECH.
a) I worked hard /aɪˈwɜrkthɑrd/; tends to elide the /h/ sound, sounding as: /aɪ ˈwɜrktɑrd/
b) He broke his arm / hiˈbroʊkhɪzɑrm / tends to elide the /h/, sounding as: / hiˈbroʊkɪzɑrm /
c) He worked here in 1970. /hiˈwɜrkthɪər ɪn1970/ eliding the /h/ phoneme and sounding as /hiˈwɜrktɪər ɪn1970/
IIIº - WITH THE OBJECT PRONOUNS (HER) AND (HIM).
I also find the object pronouns HIM and HER elide their /h/ phoneme in most of the times when the previous syllable is stressed in conversation, for examples:
d) Tell him to come / ˈtɛlhɪmtəˌkʌm / tends to elide the /h/ sounding as: / ˈtɛlɪmtəˈkʌm /
e) I told you to give her the book / aɪˈtəʊldʒjətəˌɡɪvhərðəˈbʊk / tends to elide the /h/ sounding as: / aɪˈtəʊldʒjətəˌɡɪvərðəˈbʊk /
IV° - WHEN THE AUXILIARY (HAVE) IS PRECEDED BY A MODAL VERB.
When the auxiliary HAVE is preceded by the modal verbs WOULD, COULD, SHOULD, MUST and MIGHT, the auxiliary HAVE elides its /h/ phoneme; the /d/ or /t/ phoneme of the preceding modal verb always becomes flap or tap /d/ or /t/, thus taking the /r/ sound. For examples:
f) Anything would have been better / ˈɛnɪˌθɪŋˈwʊrəbɪnˌbɛtər/
g) He could have done much more / hiˈkʊrəˌdʌnmʌtʃˈmɔr/
h) It should have been you /ɪtˈʃʊrəbɪnˈjə/
i) it must have been love / ɪtˈmʌsəbɪnˌlʌv / sometimes / ɪtˈmʌstəvbɪnˌlʌv /
j) I might have been an architec / aɪˈmaɪrəbɪnənˈɑrkɪˌtɛkt/
1) In the connected speech, the syllable preceding HIM, HER and HAVE is always stressed and end with a consonant sound, different than in isolated words which may be preceded by both, a consonant or a vowel sound.
Does this ─a stressed syllable ending with a consonant sound─ have anything to do for /h/ to lose its sound?
2) Regarding the connected speech again, I haven't seen a phoneme /h/ elided its sound when it's preceded by a syllable ending with a vowel sound.
k) I know her brother / aɪ ˌnəʊ hər ˈbrʌðər /
Could this be possible to happen with a preceding syllable ending with a vowel sound?
*The stress syllable preceding the syllable losing its /h/ sound is always a primary stress; in other words, it's the strongest one.
Hoping to receive your valuable feedback and insight.