I was watching news from TV. they were showing a news video clip so the reader was silent. When clip finished, the reader started to read news but his voice was like he was talking in a empty hall (hall effect). Within couple of seconds, they removed the hall effect totally from his voice and voice became crystal clear instantly. So I understood that there's an electronic magic hidden. Do anyone have experience about it? Do they decrease the gain or what?

 

I only think I have experienced something similar when there have been at least two microphones in the studio - and the guest's microphone has been switched off.

 

yes....the effect came from switching microphones.

 

Is that mean while in the discussion with guest, they turn on and off mic A and B again and and again according to speaker person, to minimise hall effect? if they turned on both mic, and just a person is speaking on mic A, the mic B would hear his voice with hall effect, would't it?

 

No.......it means that an audio engineer or audio tech has screwed up. Which is very common now.

And you should not use the term hall effect in this context. You should use the term concert hall effect. The hall effect means something totally different from your usage. It's a magnetic effect.

I can only comment on the information that you have supplied. Here's what I believe is going on.

Person A has mic A and is sitting at conference table with person B and mic B. Before going on air.....both mics should be switched on......AND the audio levels BEEN checked.

If this had been done.....you would here both person A and B in a normal voice. But some idiot.......forgets to turn one of the mics on. The person that has his mic on.....will sound normal......the person that mic is not on.....sounds like he is across the room......your concert hall effect.

Do you understand?

 

Agree with that hypothesis.

 

Ever watched local news when they have a fault on the tie microphone, and have to use the studio mic to fill in, same effect Hollow....

 

When two people are talking and both are wearing mics, both mics are on all the time. Yes, that means that each mic is picking up a little bit of the other person's audio, but it is so far below the signal from the local mic that the audience does not notice it. A lapel mic is about 1 ft from the wearer's mouth, but many feet from the other person. At 5 feet, that is a 25-to-1 difference in the two wave energies, or about 30 dB. What often happens in newscasts is that not all mics are turned on, and the concert hall effect you hear is the speaker being picked up by the mic next to him. A common error is when the news desk people throw it over to the weather guy, and his mic is not on. You hear him through the multiple news desk mics until the audio dude hits the switch.

ak