FORUMS: list search recent posts

White Noise from Wav Files Recovered from a formated SD card

COW Forums : Audio Professionals

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Rui Pedro Sousa
White Noise from Wav Files Recovered from a formated SD card
on Feb 6, 2018 at 4:20:52 pm

Hey all,

So we recorded a bunch of audio files for a project and the person responsible for capturing the files missed a portion of one day of shooting.

But the SD card had been formatted. So we recovered the files with "Several" recovering software and this happens in all of them:

- They recover a lot of files including files from 4 formats ago.
- They recover the most recent files (up to 20 in a perfect way)
- But all the other ones, the ones we actually need, they do play, we can hear people talking but suddenly comes White Noise over the voices. It comes and goes in intervals of 1 to two seconds.

Is there any way to fix these?

I uploaded one of the files for you to take a look at. We did find a Recovering Store but they are asking for up to 500€ to recover the files as they say the SD card needs to go to a LAB to recover this files.

Here is the file: 12133_170925005mono6.wav.zip

Thanks in Advance,
Rui


Return to posts index

Richard Crowley
Re: White Noise from Wav Files Recovered from a formated SD card
on Feb 7, 2018 at 12:44:45 am

The white-noise (hiss) you are hearing are the missing (or rather displaced) sectors/blocks on the recording media. They don't have any audio content in them, they are random ones and zeros from whatever may have been on the media at some time in the past. A "quick-format" (or "deleting" a file) doesn't actually erase anything, it just cleans out the directory so that everything appears to be empty and the sectors/blocks are available for anyone to overwrite.

The missing sectors/blocks may (or may not) be on the media somewhere, but apparently your recovery software was not successful at assembling all the sectors/blocks together. The data recovery company charges reflect the tedious task of examining every sector/block and trying to re-assemble them in the proper order. Much like putting together a 5000 piece jigsaw puzzle. Except you don't have the visual aid of being able to "see" the pieces.

However, there are many factors that could preclude anyone from completely recovering all the pieces. If a file/recording was not properly closed, then the media directory wouldn't have a complete record of all the blocks and then the next file written could write over them not knowing that they were part of a previous incomplete file.

You will have to make the trade-off decision of whether it is worth paying for them to attempt restoration vs. the tangible (and intangible?) cost of re-doing it, or living without it?

---------------------------------------------------------------------------------
Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2018 CreativeCOW.net All Rights Reserved
[TOP]