An 'extemporaneous' speech style would be considered as the delivery style in which the speaker employs notes along with some adornment to present his/her speech that helps in creating the intended effect on the audience.
As per the question, Joseph's delivery style of speech would be characterized as 'extemporaneous' as he employs embellishments like 'natural and conversational' style along with the use of 'notes' while delivering. This delivery pattern would assist him in creating the intended impact on the audience and enhances the worth of your speech. Thus, <u>'extemporaneous'</u> is the answer.
