I’m an Canadian anthropology PhD student doing interviews in China for my thesis. I use an Olympus LS-10 to record my interviews, then later, after returning to the city, transcribe the interview to a written transcript.
Yesterday I came across an important audio interview that has really messed up sound. The batteries in my recorder, an Olympus LS-10 (quite good) must have been dying and recorded a nasty buzz that changes pitches through the recording as the batteries begin to fade.
I tried to clean out the noise, but I’m certainly not very technical, and the result was terrible. I only need to be able to hear intelligible voices. It doesn’t matter if the speech sounds unnatural or not. The main thing is I need to be able to hear what is being said.
Since I am very pressed for time- and have only very rudimentary audio-related knowledge, I would like to ask if someone here might have a look at this for me and see if they can strip out enough of the buzz but leave the voices intelligible. I don’t know if the file is savable or not, but I sure hope so.
Or perhaps someone might be able to provide me with step-by-step instructions on how to remove the noise myself using Audacity or some other application.
Thanks for your useful suggestions.
I know that the varying pitch of the hum sound will make this a tough job.
I just don’t want to torture my poor assistant who must spend 9 hours typing a transcript of this conversation. If theres’ a way to reduce that annoying buzzing-hum, it will be great.
Will breaking the recording into different sections each of which is characterized more or less by the pitch of the noise?
You have the worst of all possible noise problems. A buzz or whine that moves over the course of the show, plus white noise. We will not be able to remove the hiss from the actual spoken words, but we can remove the hiss from between the words simulating a semi-quiet performance.
We will never get back to a good theatrical show.
The short version of noise reduction is select some performance with noise only and apply that to the “profile.” Then select some of the actual show and apply the filter. It will try to suck noise similar to the profile out of the show.
The amount of suck is the suppression of the noise and the other two settings have to do with protected voices – to keep people from sounding like Space Aliens. Delay is the time before and after each word and Smoothing is the vocal characteristics. 18dB reduction sounds approximately like half-way.
The early noise reduction didn’t have all these fancy-pants settings and it was almost universally terrible.
One final tweak to reduce hiss in a speech recording would be to cut back as much of the high end, (above about 6000Hz), that you can get away with before it affects intelligibility. The overall reduction in hiss by doing this will noticeable but minor.