Need help with a 911 call

[CAnn]

I don't know where else to turn, so I am seeking help here. On July 5/05 my daughter and I experienced the horrifying experience of "sudden acceleration" in our vehicle. I won't go into details here, but after going thru 4 red lights, we managed to bring the vehicle to a stop -thanks to 911. 911 won't give out transcripts or a copy of the 911 tape (policy), but they let me listen to the call over the phone and I can go into their office. Here's what I did..using Ulead Video Studio, I taped a microphone to the receiver of the phone and recorded the call as a wave file. On the other, she put the phone to the recoding.. Now, although I can hear it with speakers turned up full, I would like to (1) increase the volume on the wave file and I don't know if possible..but (2) clearify it a little more. I don't want to go out and buy equipment to do this; however, I do have software.. as I am in the process of converting VHS to DVD . I also have virtual VCR and VirtualDub as well as Canopus Procoder 1.5. (but I am just learning this stuff, so not real proficient) Please can you help me? How do I do this (if at all possible) I really would appreciate any help you can give me!! Thanks

[Mug Funky]

yikes!

hmm... you can capture the video (i'm assuming DV, yeah?) into type-2 avi format with procoder i think. at any rate there's free tools available to capture with (scenalyzer live is a good one. it'll watermark frames with the free version, but it doesn't touch the audio which is what you really need).

once you have an avi file, you can load it into virtualdub, go to the audio (or "streams") menu, and rip the audio out as a wav file.

you can then take this wav into an audio app to polish it a little. if the words are discernable in your original recording, then you can make it sound better. i tend to use cool edit pro (now called adobe audition, but basically the same program) to do stuff like this.

it'll probably need equalisation to get rid of the plastic resonance in the phone receiver, and hiss/noise reduction for the considerable hiss you'll have after amplifying it to a good level. don't go nuts with the noise reduction, as it can very easily remove important aspects of human voice as well (voices are both tonal and impulsive, and NR fixes tones well, but sucks at impulses, so voices suffer a bit when the NR is turned up too high).

definitely do not save over that original recording though - anything you do to it in an audio app will reduce the amount of information in the recording, not increase it. the benefit is it'll make it more useful at the cost of hopefully small precision loss.

[CAnn]

I have the audio as a separate wave file..not attached to a video file. Do you know of any freeware audio app that I can use. I don't have the Adobe audition? Thanks for suggestions!

[user44]

I'm sure some hunting around might find you 'SoundForge' used to be made by SonicFoundry, untill that was Bought out by Sony. (there's a Demo you can try online), and if your a little more creative *cough* I'm sure you can work things out.
That should help you clean things up, use the Dynamics Presets to clean up the audio, then maybe boost a few of the Dynamics too before putting it thru the mastering compressor.

[mic]

If they'll let you listen into the call again over the phone, you can buy (for ~$10 I think) a nice adaptor from Radio Shack -- it plugs into the phone lines, and can be plugged into any tape recorder or input on your PC's sound card. This will give you good clarity.

For enhancing the file, I'd recommend shareware Goldwave, which has a good noise filter.

FWIW, Personal opinion and all that, I'd record to a new tape, recording that to your PC for enhancing -- I'm no lawyer but a doctored wav file, if only enhanced for clarity, is still doctored.