Merriam-Webster defines "Ambience" as:

   1.

      :  a feeling or mood associated with a particular place, person,
      or thing : atmosphere
      <http://www.merriam-webster.com/dictionary/atmosphere>


In the production side of the film/TV industry, the location mixer will 
often ask for "Quiet on the Set" so the room tone (ambience or part of 
atmospheres collection) can be recorded to be later used in post 
production to match ADR with the original production dialogue.

Regards,

Corey
Corey Bailey Audio Engineering
www.baileyzone.net

On 10/26/2016 9:29 AM, Don Cox wrote:
> On 24/10/2016, Lou Judson wrote:
>
>    
>> The only way to measure it would be in a silence of the musicians, and
>> subtracting the surface noise of the disc. Usually empty room time is
>> edited out.
>>
>>      
> I think ambience is the complex set of reverberations and echoes
> produced by each instrument in each position in the room.
>
> It isn't the noise you might detect in the same room when it is empty.
>
>    
>> Izotope RX detects and can remove or measure it, even show you a
>> visual representation..
>>
>> Perhaps if you describe why you want  to knwo wecould be more helpful.
>>
>> <L>
>> Lou Judson
>> Intuitive Audio
>> 415-883-2689
>>
>> On Oct 24, 2016, at 11:37 AM, Steven Smolian<[log in to unmask]>
>> wrote:
>>
>>      
>>> Ambience of the room.
>>>
>>> Steve
>>>
>>> -----Original Message-----
>>> From: Association for Recorded Sound Discussion List
>>> [mailto:[log in to unmask]] On Behalf Of Lou Judson
>>> Sent: Monday, October 24, 2016 2:21 PM
>>> To: [log in to unmask]
>>> Subject: Re: [ARSCLIST] Ambience
>>>
>>> Are you meaning signal to noise? Or the ambience of the room it was
>>> recorded in?
>>>        
> Regards
>