I want to generate random numbers within a certain range (1 to 26) using a .wav file with only static noise.

The results need to be repeatable.

Is there any service/program/method of accomplishing this in Windows 7?

  • 1
    What do you want to do with the random numbers? The answer to this question affects which method will be best to do this.
    – jmetz
    Aug 1, 2012 at 14:29
  • First of all, do you know any programming languages? I assume not but that doesn't change the fact that random generated numbers that are repeatable are not random at all. That said, you may consider hashing the file with MD5 and use the hash as a seed. That will guarantee that the seed is unique to that sound snipped can reproduce predictable sequence of numbers. However, this is NOT random.
    – anber
    Feb 7, 2014 at 5:54
  • @anber Yes, I have experience from a couple programming languages. From what you wrote, I will keep that in mind. Thanks! ;)
    – slippery
    Feb 8, 2014 at 5:34

3 Answers 3


Try Python's scipy module,

import scipy.io.wavfile as sio

data = sio.read(FILENAME)
data = data[1].astype('float')
data -= data.min()
data *= 25.0*data.max()
data += 1

The data is now a vector and can be saved or used for further processing etc.

If, for example, you just want to save the output as a csv (comma separated values) file, you could then use

import csv
fout = open('output.csv', 'w')
wrt = csv.writer(fout)
  • i unfortunatly dont program/know python. How could i use this snippit of code?
    – slippery
    Jul 31, 2012 at 23:01
  • 3
    @zeldarulez: As long as you can think logically, Python is one of the easiest programming languages to learn. Jul 31, 2012 at 23:11
  • @zeldarulez - what do you want to do with the random numbers?
    – jmetz
    Aug 1, 2012 at 14:12
  • i would like to use the use the random numbers to create a one-time pad key. I know about random.org, but i want to use a method to create it myself
    – slippery
    Aug 1, 2012 at 16:33
  • @IgnacioVazquez-Abrams learning a new language will be ok ;)
    – slippery
    Aug 1, 2012 at 16:39

I have created true random number file using AM radio waves or what is popularly called white noise. I've done it in Linux, so if you want that, follow these steps.

  1. Use your radio that has AM.
  2. Put frequency somewhere between radio channels - you should get white noise from radio waves and other magnetic interference.
  3. Use Linux distro (Debian/RedHat based) - I have used Ubuntu.
  4. Install "sox" (bundle) application, which has a small app called "rec" that you will use.
  5. After you installed sox, place your microphone to the speakers so they can record "white noise" and use this command:

    rec -c 1 -r 8000 -t wav -e signed-integer randomWAVfile

In short:

  • -c 1 (you are using one channel)
  • -r 8000 (sampling of 8000 Hz)
  • -t wav (format file as wav)
  • -e signed-integer (and reads 16 bit at the same time)
  • randomWAVfile (file name - by your personal preference)

You will have a file with random noise that is "formated" as wav file (it holds wav header of 14bits - if I am not mistaken).

To strip down the header and "remove" potential duplicates, use this program written in C by Rick Van Reinn.

It is not a big issue, but be aware that castings in this program is not correct and your gcc will start to complain.

Source code link: Openfortress source code

By pushing down the file through the program:

cat randomWAVfile | ./noise-filter > randomBits

you will get the TRNG file.

I have learned that by using this link. The only thing the guy who created the original tutorial were using ancient versions of Linux that operated with OSS (open sound sys) and not alsa.

Original post: Openfortress original link

  • Please read the question again carefully. Your answer does not answer the original question. OP said "The results need to be repeatable."
    – DavidPostill
    Feb 22, 2016 at 23:05
  • Sorry David, I was browsing something and haven't red question carefully. My apology. Feb 23, 2016 at 16:46

If the file is PCM-encoded then you can use Python's wave module to read the samples in the file, and then fold the values into the range.

  • 4
    The wave module reads the data as a string - I would recommend using scipy.io.wavfile instead as I posted in my answer - it makes the data much more manageable for the subsequent rescaling.
    – jmetz
    Jul 31, 2012 at 21:41

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