High pitched admen

I've noticed a lot of ads on the radio are speeded up to where the man's voice is a higher pitch than normal. I don't know if they do this to put more words in the time slot or if they do it just to be annoying. I studied in Marketing classes back in 1978 that when ads are annoying they get noticed and the person listening things about the message more often than a pleasant ad that he doesn't pay attention to. I don't like it but I understand it.