You will be amazed at what can be heard by a microphone.
I'm going to be get up on my soap box and give you my point of view as a location recordist and audio post engineer.
Sit down in that room in total silence for about 10 minutes at different times of the day and listen to all of the sounds that are present.
If your location is near a road the traffic patterns will be different depending on the day and the hour of the day. There are probably neighbors and their patterns will shift as well. Do the neighbors have kids or pets that might run around? Near an air traffic pattern, a subway, a railroad, a truck stop, a hospital, a police station, a firehouse, a school, a church or town hall with bells?
Is there a 'fridge in the next room? Does the light over the stove hum? A buzzing lamp in the hall? A clock ticking somewhere? Does the clock radio give off a hum? Even when asleep PCs make a little noise, so do cable boxes. All of these thing should be turned off!!!
Is the room very resonant? You may need to put up some sound blankets and lay down some carpeting.
Watch the talking, even in whispers. "Soft" shoes only for the entire crew and clothing that doesn't make noise. Wooden floors can be a nightmare when the talent wears hard shoes. Put soft soles on them or put down some carpeting if the floor won't be in the shot. Old floors also creak. Make sure hard floors are swept before rolling. That little piece of grit can sound huge later on.
I recently worked on a project where the director was in love with a particular indoor location. The location recordist and I both objected as strongly as we could because it sat between train tracks and a highway and was in an air traffic pattern. After editing each shot had a completely different background ambience. The wide shots were mostly car traffic, the two shots and close ups were a crazy mix of jets, trains and trucks. It was absolutley impossible to make it smooth or believable sonically.
On another project the outdoor location was on a large piece of property so was fairly quiet as far as man made sounds were concerned. The problem arose when the wind would carry the chimes from a nearby church. The shoot took three times as long as it should have because every 15 minutes we had to wait for the damned bells to stop ringing.
Had an intern cable wrangler on a set once who wore courderoy pants. SWISH SWISH SWISH!
This one came in for audio post. Big old antique grandfathers clock in the library down the hall. They even remembered to turn the chimes off but forgot to stop the pendulum. Every time the shot changed the ticking would stutter or even echo when the dialog was cut to overlap. They ended up doing ADR for the entire scene; if they edited to keep the ticking in sync the scene lost it's power. The ADR was very good, but didn't have that special intensity of the location dialog. The scene also had to be Foleyed.
Another one had the talent in boots on a hard wood floor. Every time she walked it was like King Kong headed for the kill!!!
I can't even begin to tell you how many times I've had to cut out the crew talking or moving around.
I could go on, but every example I gave at the beginning has at one time or another been a problem during audio post. Most indie film makers do not have the luxury of Holloywood budgets or scheduling. Many big budget films are anywhere from 50% to 90% ADR!!! However, the footage is ready for ADR within 24 hours. If the talent is not required on the set the next day they can do their ADR work. The talent is still in character, which makes for great continuity as far as the voices go. It enables the dialog editor to substitute single words and phrases instead of entire lines. It also helps that the talent knows how to do ADR.
One of the reasons ADR is so prevelent in big budget productions is that sets are becoming noisier. Another reason is that, if you have the budget, you can sonically make it entirely believable and have the ability to artistically enhance the scene with sound design to a remarkable degree.
Okay, I'll get off my soapbox. It's just very frustrating for all of us audio types that so many young film makers don't think about sound until the audio post process, and by then it's too late. As Steven Spielberg says, "Sound is half the expereince." Many of the "classic" films of the last 30 years or so have had the sound designer involved during pre-production.
Now I'll shut up.
