Filtering my voice and the one of the person talking with me

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Tonyzh
Posts: 1
Joined: Tue Jun 01, 2010 12:52 pm

Filtering my voice and the one of the person talking with me

Post by Tonyzh »

Hello,
I'm a new user of Goldwave.
I have recorded a conversation which is very important for me, but it was on the street and after that it continuous in a classroom. The problem is that it's not that clear, because of all cars driving next to me in the time I was talking on the street and also in the time I was in the classroom I was talking with that second person which seats next to me, but the professor was talking too loud and it's not clear what I recorded of my conversation.
Could anybody tell me how can I do to eliminate that noise of the city in the time I was outside and the voice of the profesor in the time I was in the classroom?
Thank you all in advance for your help.
Thank you and best regards,
Antonio
DougDbug
Posts: 2172
Joined: Wed Feb 16, 2005 3:33 pm
Location: Silicon Valley

Re: Filtering my voice and the one of the person talking wit

Post by DougDbug »

:( It's going to be pretty-much impossible to clean-up your recording.... Just as a point of reference, most "on location" movie dialog is re-recorded in the studio, because it's impossible to remove the background noise. On-location news reporters speak directly into the microphone to overcome background noise, but this is only partially effective and you often can hear backgrond (or foreground) noise.

1. You can try experimenting with the equalizer (Effect -> Filter -> Equalizer) to try an bring-out the voice frequencies. However, there is a lot of overlap with the voice and noise frequencies.

2. You can boost the volume where the desired voices are talking, and reduce the volume when there's noise-only. (You can use Effect -> Volume Change or Effect -> Volume ->Shape.)

3. You can try some compression (Effect -> Compressor/Expander -> Boost Quiet Parts) when there is noise & talking together. (This may help, or it may make things worse.)

NOTE - GoldWave has a Noise Reduction filter, but this works best when you have a constant low-level background noise, like tape hiss. When you have a high level of noise, you can't isolate & remove the noise without also affecting/removing some of the "signal".
cdeamaze
Posts: 87
Joined: Thu Oct 05, 2006 3:19 pm

Re: Filtering my voice and the one of the person talking wit

Post by cdeamaze »

The voiced speech of a typical adult male will have a fundamental frequency from 85 to 180 Hz, and that of a typical adult female from 165 to 255 Hz. In telephony, the usable voice frequency band ranges from approximately 300 Hz to 3400 Hz. Thus, even though the fundamental frequency of most speech falls below the bottom of the "voice frequency" band as defined above, enough of the harmonic series will be present for the missing fundamental to create the impression of hearing the fundamental tone. Not surprisingly, our plain old telephone system(POTS) works fairly well most of the time.

Borrowing the ideas from our POTS, you may wish to bandpass your voice to between 80 and 3400Hz or, if you don't mind filtering it twice, lowpass to below 3400Hz then highpass to above 80Hz. The next step you may need spectrum analysis tool such as spectrogram.
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