This is the 3203rd most frequent Spanish word.
ambulancia
Ambulancia: A vehicle used for transporting sick or injured people to medical facilities.
In this sentence, 'ambulancia' is used as the subject of the prepositional phrase, referring to the specific emergency rescue vehicle emitting the siren.
Escuchamos la sirena de una ambulancia acercándose.
We hear the siren of an ambulance approaching.
Here, 'ambulancia' functions as the subject of the sentence, directly involving its operation and purpose of transport.
La ambulancia lleva al paciente al hospital más cercano.
The ambulance takes the patient to the nearest hospital.
In this usage, 'ambulancia' appears as the direct object, representing what is being called for emergency response after an accident.