Chabad.org — English translation + Rashi
Torah Temimah: from “ותקעתם תרועה” we learn a plain tekiah before the teruah and after it.
English: “And you shall sound a teruah” — a plain tekiah before the teruah; “a teruah they shall sound” — a plain tekiah after it.
Frame of teruah — tekiah surrounds the teruah on both sides.
The journey-signal is a structured sequence, not a single cry.