What causes that terrible hissing sound when you make a recording, and how can I prevent the hissing sound from appearing in the first place (rather than having to use some audio editing software to get rid of it later)?
If I record complete silence and play it back, I just hear hissing, and it's actually a surprisingly LOUD hissing noise...from complete silence! The problem is the sounds I do hear from the neighbours are very quiet through the wall, so the loud hissing on the recording overpowers the faint noises to the point where I just end up deleting the recording (not even audio editing can save these files). What a waste!
I can't isolate the source of the problem:
I've tried so many different recording apps on my Android phone, they all sound terrible
I've tried recording in AMR vs MP3 format, and that doesn't make a difference
I've tried recording with the phone cover on and off, and that doesn't make a difference either
I'm sure it's not a hardware problem either, because it's a new and powerful Android phone (Samsung Galaxy S3)
Please help, so that I can start getting some good recordings.
In a nutshell, what you're hearing is low quality hardware. I'm not saying your phone sucks as a phone, I'm saying that the microphone will be a tiny cheap electret condenser with a limited frequency response, with any other hardware involved being pretty naff in terms of audio fidelity, and there's likely some software based rolling of low end and enhancement of high end for vocal clarity happening that you might not be able to switch off. It all makes sense in terms of production costs and nice clear phonecalls, just makes less sense if you want your phone to be able to record your neighbours doing the nasty LOL. Basically, better sound requires less portability and more money. Phones can be a lifesaver when the action is loud and clear, but hardware like that is only going to perform up to a certain level no matter what you do.
That said, there are ways of reducing hiss that are more effective than others, so if you want to upload anything, I'm sure a few people here would have a shot at cleaning up.
I agree with Scott, the Problem is your low Quality Audio Recorder (phone). I would recommend you invest in a decent Recorder (starting at around 50 euro). especially if you want to record through walls!
Low quality hardware is one of them. Also you are typically trying to record very faint sounds swimming in a sea of natural noises.
If your phone has a mic input jack you may have better luck using an external microphone that has lower self noise. If you can solder up a cable the best inexpensive mic I have found in terms of noise is the BT-EM172. You should be able to find these for about $11 a pop on the internet. I would also suggest that you build a battery power supply for the mic as they preform much better with a higher supply voltage than most devices provide. Also an independent battery will not have any electrical noise on it from the rest of the phone.
The second issue, the faint sounds in a sea of other noises. Try and identify them and cut them out. Turn any heating or A/C off. Turn any fans off. Pull any window blinds to keep street noises out as much as you can. It is hard to be objective as to noises with your ears as your brain tends to tune the noises out, but the recorder will not. Much like you can not trust your eyes for color balance. With practice you can become much more objective.
The other nice thing with an external mic on a thin wire is you can sometimes get closer to the sound source. If you travel with saya leatherman you can unscrew and outlet cover and slide the mic into the wall cavity, or unscrew the ventilation grate in the bathroom and often times get the mic just about up against the grate in the next room. Bring some blue painters tape and the wire from a coat hanger and you can snake the mic into some amazing places and use the painters tape to hold the coat hanger wire in place. The painters tape will peel off with no damage to the paint.
iPhones have a lower noise floor than practically every Android device I've tested, lower still if you go for an app which bypasses the native iOS DSP. Granted, they're still not gonna stand up to a decent dedicated recording device, but as phones go, iPhones don't do too bad of a job. IN any case, the original poster is using a Samsung S3.
Also, I've never tested it but I think there might be a difference between the iPhone's internal mic and the mic on the earbuds. I've tried using the earbud microphone and it worked well. I think it may have more low end roll off. But, then again, I've never really compared the 2.
Very few questions asked when some innocent bystander wanders into the corridor and you're holding an iPhone. Not quite sure how you would explain holding a full on mic kit or the equivalent of a dictaphone... Ha ha!
