Timeline for Why isn't silence just zeroes in an audio file, and how can I make it?
Current License: CC BY-SA 4.0
15 events
| when toggle format | what | by | license | comment | |
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| Feb 20, 2023 at 20:27 | history | edited | Patrick O'Brien | CC BY-SA 4.0 |
added 389 characters in body
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| Feb 20, 2023 at 20:23 | comment | added | Patrick O'Brien | @user253751 Yeah my bad, I was originally asking a different question that had the details and I mistakenly removed that part along with the other stuff I removed. I'll edit it. | |
| Feb 20, 2023 at 20:21 | comment | added | Patrick O'Brien | @TimWescott In Audacity: Generate > Silence... : Set duration to 00h00m01.000s > OK | |
| Feb 20, 2023 at 16:38 | comment | added | robert bristow-johnson | Well, @DmitriUrbanowicz , I know a thing or two about dither myself. And I know the difference and roles of the Probability Density Function (p.d.f.) and of the Spectral Density (a.k.a. Power Spectrum) is. And they are different. To completely decouple both the first and second moments of the quantization error (using a uniform quantizer) from the signal being quantized, triangular p.d.f. of width of two quantization steps is exactly enough. Independent of the spectral density. | |
| Feb 20, 2023 at 7:02 | comment | added | Dmitri Urbanowicz | @robertbristow-johnson apparently, such an amplitude is required if the noise is high-pitched rather than white. | |
| Feb 18, 2023 at 20:44 | comment | added | Hilmar | Audacity works internally with 32-bit floats. When you create silence it creates float zeros. What you see happens when you export the file to wave format. It applies "dithering" to decorrelate the quantization noise from the actual signal. See manual.audacityteam.org/man/dither.html | |
| Feb 18, 2023 at 20:38 | comment | added | jpa | Yeah, happens for me too. I don't see a reason why it needs to happen, considering floats can represent 0 exactly. And the same happens even if I create the track at 16-bit PCM in Audacity. When I export as 32-bit float RAW, it gets all zeros though. Related manual section. | |
| Feb 18, 2023 at 19:53 | comment | added | TimWescott | How did you "generate silence"? Did you, perchance, record a second of input from an unplugged microphone jack or some such? | |
| Feb 18, 2023 at 19:44 | comment | added | TimWescott | Well, now we know what the Sound of Silence looks like, at least. | |
| Feb 18, 2023 at 17:40 | history | became hot network question | |||
| Feb 18, 2023 at 17:40 | comment | added | robert bristow-johnson | There is this (since 1990) commonly-used technique of dithering but that seems to be a little intense. I would not expect dithering to be toggling the bottom 4 bits (which is what going from -7 to +7 is). I would expect the bottom 2 bits to be toggling. Like going from -1 to +1 with a few 0's in between. | |
| Feb 18, 2023 at 11:15 | answer | added | Marcus Müller | timeline score: 5 | |
| Feb 18, 2023 at 10:55 | answer | added | Justme | timeline score: 19 | |
| S Feb 18, 2023 at 9:23 | review | First questions | |||
| Feb 18, 2023 at 11:16 | |||||
| S Feb 18, 2023 at 9:23 | history | asked | Patrick O'Brien | CC BY-SA 4.0 |