Radio Trailers

After listening to a number of radio trailers, there are several convections shown in  the examples provided.  Dependent on what is being advertised ,the trailers and adverts can vary widely. A film trailer is different from the advert for a retail product or an informational ad.
One of the most prominent convections in the trailers is the clear sounding voice. In all examples the voice is prominent and normally brought to the front of the audio. This helps to convey the message more clearly so it is  easily understood by the audience. Many radio trailers also include some sort of background music, or noise that is non-diegetic to the rest of the trailer for example the noise of a jet when advertising super fast broadband.