... perhaps I can record some other outdoor noises, that you can hear but not see, cause they are out of frame. Hopefully it will add to atmosphere as well. I thought about construction workers making noise, but there is none of that going on to record right now...
I already put sounds of a dog barking off in the distance, in the movie. I just thought it would add a layer (shrug). I wanted seagull sounds for another scene but they have all migrated unfortunately.
Now you are touching on the area of professional level sound design, rather than the usual level of indie sound. The sounds which go into the atmospheres give the scene it's setting. When I was a university lecturer during one of my introductory classes to sound design, I used to play the students a scene of a worried grandmother in a sitting room having a conversation on the phone. I would ask the students what sort of building that sitting room was in and where the building was. After looking at me blankly (as students do!) for a few seconds they would eventually come up with the right answer, an apartment in an inner city tower block. They couldn't explain how they knew this though. This is the power of professional sound design, we'd put in the sound of heavy traffic and other sounds common to a poor inner city area but removed the frequencies and added other processing to correspond to those sounds being very distant and being heard through a closed window. This atmos was then mixed so low with the rest of the sound of the scene that it was almost inaudible. It was still just enough though to sub-consciously provide the location and context of the scene. How does this apply to what you're doing? Creating an atmosphere is not just about throwing some sounds in the background of the mix. You have to ask what you want to achieve and what scene you want to set. Dogs barking implies a poorer neighbourhood, birdsong implies spring or summer and a suburban or country location, etc. etc. This might seem like insignificant details but when it comes to sound design these details have a significant impact precisely because they are perceived sub-consciously.
I get what you mean about indie's not having enough sound. Perhaps that's the reason why at a local film festival, a lot of the movies just seemed quiet or like there was something missing.
Certainly the amount and depth of the sound is frequently an issue but there's an even deeper level as well that is almost always entirely missing. Using the example above of the atmos containing dog barks; what sort of dog barks? What breed of dog, how stressed, how aggressive, alarmed, what speed? Details like this can add tension and pace to how the audience perceives the scene even if the audience can barely hear the dog bark. You can build a scene with an number of these almost insignificant details, plus a bit of subtle processing and voila, you've created a sound scape which sets the scene in terms of: Time, location and most importantly, emotional response. This is Sound Design! When used coherently throughout the whole film and even to aid character development, This is the true meaning of the term "Sound Design". Sound design is NOT just the act of cutting in a few seemingly appropriate sound FX. Sound Design and Sound Designer are two of the most incorrectly used terms in fimmaking IMHO!
So in answer to your question, yes, adding depth is essential. You are on the right track but just scratching the very surface of sound design. If you think about it, you can use: Construction sounds, dog barks, seagulls, cicadas, a breeze through the leaves, aeroplane/helicopter noise, police sirens, church bells, distant thunder, prayer calls, sports crowd noise, sheep bahs, other road traffic noise, geese honking, train/tram/metro noises, cows mooing, fog horns, factory noise and so on almost ad infinitum! And, not only are there an almost infinite number of sounds you could use but you also have the choice of a wide variety of types/colours of each of those sounds. The question is, which ones best set the scene, create the energy/pace and elicit the emotional response the film requires? It's this understanding and use of Sound Design which is so lacking in indie films and why they so often feel slow, boring and/or seem to be missing something.
Trying to record everything you need for good sound design is going to be impossible without a team of people and serious amounts of time and money but there is a solution (albeit imperfect) for those with very limited/no budget, cheap or free online sound FX libraries like SoundDogs.
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