Listening audioscript

THE MAN GIVES HIS OPINION OF THE PROPOSAL. STATE HIS OPINION 
AND THE REASONS HE GIVES FOR HOLDING IT. 
[90 second pause/response time] 
 
SPEAKING QUESTION 4, Speaking Skill 10 
 
Example Question 4, Listening Passage A, Page 271 
[ mp3 112]
 
Now listen to a lecture on this topic in a physiology class. 
(Professor) 
OK now I’m going to give you a few examples of how the different 
distribution and light sensitivities of these two types of photoreceptors 
affect visual perception. You’ve probably observed these effects, but you 
may not have known the explanation before. 
Because only the rod cells are sensitive to very low light, say at night 
or…or in a room lit by
candlelight, you don’t see colors in these situations. Think about it. At 
night, the cones
don’t function due to the faint light, only the rods. But, because only
the cones allow us to see in color, everything is black and white. It’s only 
when there’s more light, um…like under a streetlamp at night, or uh 

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LPREP IBT 3 E AudioScript 
77
when someone turns on the main lights in a dark room that things 
suddenly acquire color.
You can also see effects of the sensitivity and distribution of the rods in 
action if you look at a very dim star in the sky. You might have noticed 
before that a star such as this can be seen if you look a little to the left or 
right of the star. But if you look directly at the star, uh…I mean, center it 
in your field of vision, the star disappears. Move your focus a little away 
from the star and it suddenly reappears. This is because of the 
concentration of the very sensitive rods outside the center of your field of 
vision, a little to the left or the right, and the lower light sensitivity of the 
cone cells at the center of your field of vision.