Sentences can be formed by phrases or clauses, in this case the italicized words are a phrase. A phrase is a grammatical unit composed by a set of words without subject and predicate whereas a clause is a grammatical unit formed by a set of words that includes a subject and a predicate.
The noun phrase “Wishing to be heard” is modifying the noun “speaker” since it is providing an explanation of why the subject is performing an action.
An expedition is an organized journey that is undertaken for a particular purpose, like a group of scientists launching an expedition to South America to seek out a new medicinal herb.
