PLEASE CLARIFY UNITS OF WAVEFORM AND WAVEFORM(dB)

Effects, Recipes, Interfacing with other software, etc.
Forum rules
If you require help using Audacity, please post on the forum board relevant to your operating system:
Windows
Mac OS X
GNU/Linux and Unix-like
Post Reply
elliew398
Posts: 2
Joined: Mon Jun 15, 2009 9:17 am
Operating System: Please select

PLEASE CLARIFY UNITS OF WAVEFORM AND WAVEFORM(dB)

Post by elliew398 » Mon Jun 15, 2009 9:25 am

this may sound straightforward, but could someone please explain the units on the y axis of the waveform spectrums - perhaps these should be more clearly marked on the programme, I am using Audacity ® 1.3.6 (Unicode). What are the units?, how is the waveform displayed? how is this calculated? should there be a 0 value on the logarithmic decibel scale? Please stick to layman's terms and respond quickly!!!! ;)

kozikowski
Forum Staff
Posts: 68941
Joined: Thu Aug 02, 2007 5:57 pm
Operating System: macOS 10.13 High Sierra

Re: PLEASE CLARIFY UNITS OF WAVEFORM AND WAVEFORM(dB)

Post by kozikowski » Mon Jun 15, 2009 3:34 pm

The waveforms represent the motion or vibration of the air during sound. It's a picture of your sound performance.

The default presentation is in percent, zero to 100 (or 1 on the scale). It's handy to view the waveform like that and it's totally logical, but it's not how your ear works. Your ear perceives half loudness or volume at about 12%.

The other display is more correctly dBFS, dB Full Scale, not just dB. Zero dBFS is the point that the digital signal is so loud that it can no longer increase. It's a mathematically precise place. So yes, the two zeros don't line up at all. dB is handy because that's how your ear works. -18dB is about half volume, and some people (young women) can still hear things at -60. That's 0.1%.

dB works best if you make the waves really tall. Grab the display by the bottom and pull. You can also split them. Make the top one taller than the bottom.

Koz

elliew398
Posts: 2
Joined: Mon Jun 15, 2009 9:17 am
Operating System: Please select

Re: PLEASE CLARIFY UNITS OF WAVEFORM AND WAVEFORM(dB)

Post by elliew398 » Mon Jun 15, 2009 4:59 pm

Thank you so much!

Gale Andrews
Quality Assurance
Posts: 41761
Joined: Fri Jul 27, 2007 12:02 am
Operating System: Windows 10

Re: PLEASE CLARIFY UNITS OF WAVEFORM AND WAVEFORM(dB)

Post by Gale Andrews » Mon Jun 15, 2009 5:04 pm

Also see this page in our draft 1.3.7 Manual and some disorganised information about Decibels here.

Please ask all your questions on the Forum, not send multiple private messages to developers and Forum moderators.


Gale
________________________________________FOR INSTANT HELP: (Click on Link below)
* * * * * Tips * * * * * Tutorials * * * * * Quick Start Guide * * * * * Audacity Manual

Post Reply