Juncture "the relationship between one sound and the sounds that immediately precede and follow it" (Roach 1991: 129) (Roach 1991: 128-129)How do we differentiate between the sequences in connected speech?
Ice cream - I scream
aɪs kriːm - aɪ skriːm
If we say that it is because phonetically they are realized as,
we are saying that there is a PHONEMIC contrast between [k] and [kʰ] which doesn't exist when we look at words in isolation. Note that the aɪ in ice is shorter than in the first person pronoun I as it is followed by a voiceless alveolar fricative and the latter is an open syllable. If you look carefully at the images (the [k] is the white space), you will see that the pronoun I is longer.
Also note that as ice-cream is a compound, the stress is on ice and that in I scream the sentence stress would normally be on scream.
In the following example both rain and train would normally receive sentence stress. As we can see in the image for my train, the coloured part is the aspirated [tʰ]. Notice also that the diphthong in might [aɪ] is shorter than in my for the reasons explained above.
might rain - my train
[maɪt̚ ɹeɪn] - [maɪ tʰɹeɪn]