Decibel/ volume reader

Hello there
Can my audacity program detect the volume of sound in say decibels?

If you mean the acoustic loudness of the sound in the air (dB SPL), no.

Your microphone and soundcard are not calibrated and your “recording” volume affects the digital level too. So, different microphones/computers/setups will read differently.

You can find the digital dB level of the file (dBFS) but again it’s not calibrated, and “loudness” or “volume” are a little tricky. The acoustic & digital levels are directly correlated, so if you decrease the loudness by 3dB the digital level will also decrease by 3dB.

Audacity’s meters show dB (dBFS) and if you click the little drop-down arrow to the left of the waveform you can change the scale to dB.

NOTE - The 0dB SPL reference is (approximately) the quietest sound humans can hear and dB SPL values are positive. The 0dBFS reference is the maximum integer value for the number of bit and the dBFS values are (usually) negative. Audacity uses floating-point internally so it can “temporarily” go over the 0dB maximum.

I was more trying to monitor the volume of my voice

I only use audacity for basic recording tasks; so could you kindly tell me where/ what the drop down menu is for the wave form?


Raw recording of your voice can be measured with the Audacity bouncing sound meter and the blue soundwaves on the timeline.

The sound meter should bounce up roughly between -6dB and -10dB.

The blue sound waves tips should reach up to about half-way—0.5 (50%).

That’s a good comfortable volume between too high overload damage and too-quiet noise problems.

Your sound meter will look different, but concentrate on the right-hand side.
Screen Shot 2018-02-06 at 16.01.17.png

could you kindly tell me where/ what the drop down menu is for the wave form?

[u]Track Dropdown Menu[/u]

By default the waveform scale goes from 0 (silence) to +/- 1.0 (maximum). If you select Waveform dB, that scale will switch to a dB.

I understand a bit more about the blue sound wave on the time line now, and I found the drop down menu to change it into db. It kind of works like a mirror as the louder the sound the more it increases bough sides from the middle. But what I don’t understand about it is the measurement. It start out at 60 in the middle and as the sound increases the number goes down and this should be the other way round!

And I see the sound meter now. But as above the more sound you put through the higher the gauge goes but the number decreases. So again it makes no sense what the db of sound actually is.

Also what is the highest db it can record?


It’s not 60dB. It’s -60dB.

Sound starts out at 0dB maximum loudness and goes quieter to the digital limit, -96dB. It’s important to keep that “-” in there. The numbers actually get smaller.

That bothers everybody. I saw one page where they decided to start measuring at the quiet point and go up. So maximum volume is 96. The problem with that, past the obvious need to do advanced math (Quick, what’s 7dB lower than that?) is that it changes with the sound standard. 0dB overload is always the same no matter what standard you’re using.

Except one. Audacity uses an internal standard of 32-bit floating. This is to keep the effects and filters from causing problems. It does not overload at 0db. You can accidentally make sound damage while you’re editing, but recover very easily later.

Changing the blue sound waves into dB may seem like a terrific idea, but it pushes the most used sound range way up into the top of the display. AudioBook voice corrections, for, example are in the top 2 and 3dB range. That’s impossible to measure in dB Waveforms.

That’s not to say the percent range of blue waves is useful, either. There’s is a request posted to keep them the same but label them both in dB.


If you’re doing spoken word, it is recommended that the sound meter peaks at between -10dB and -6dB and the blue waves tips are around 50%.

Note that’s with the waves in percent.

If you reach 0dB outside of Audacity, the sound will be permanently damaged and sound terrible—crackling and popping.

Recording low volume isn’t safe, either. Audio electronics all make quiet noise. Usually ffffffffffff—spring rain in the trees. If you record too low, you and the ffffff sound will start competing with each other.


I’ve determine the missing value (through advanced maths).

Comfortable reading volume should fall somewhere between -6dB and -10dB on the bouncing sound meter (roughly the yellow segment), and the blue wave peaks somewhere between 50% and 30%.

And just to give you the feel of why we use dB at all instead of percent for everything, -60dB is a real sound value. It’s a value of background noise measurement required for audiobooks, so most audiobook readers are very clear what that is. It works out to .001%. or 1/1000.

You can’t see that on the normal Audacity timeline. The blue waves have turned into flat, straight lines a long time ago, and remember, audio CD quality sound keeps going to -96dB. Percent values don’t map to audio very well.


So if the meter starts off at -60db, then when the meter gets to 0, dose that actully mean it is 60db?

for the purpose of my task it will be one note sang at 400hrz (G#4-A4) between 100 and 130db

Now on the sound meter in your image, it stars off at -93 and goes upto 0. But on my program of Audacity it stars at -57 and goes up to 0; so what is happening hear?
is -57 and -93 absolute zero?


“dB” is not a unit of measurement.
“cm”, “kilogram”, “dollar”, “degrees centigrade” etc are all units of measurement, but “dB” is not.

“dB” is a “ratio”. It is a comparison of one magnitude to another. A measurement in “dB” says how big something is compared to something else.

When working with signal levels *as in Audacity", the reference level is “full scale”, which in Audacity’s case is the hight of a track.
The reference level when working with “dB” has the number 0 (zero). Thus, a waveform that touches the top or bottom of an Audacity track has a level of 0 dB.

Audio waveforms should normally be less that the track height. In other words, less than 0 dB, so normal waveforms in Audacity have negative (less than zero) dB levels.

When measuring the intensity of “sound”, a “dB meter” is commonly employed. The reference level (0 dB) for audio dB meters is normally specified as “20 micropascals”, which is equivalent to “0.98 pW/m2 at 1 atmosphere and 25 °C”. This figure is nominally the “threshold of hearing” - for someone with excellent hearing, sound pressure levels for a frequency of 1 kHz greater than 20 micropascals will be audible, but below 20 micropascals will not be audible. Audible sounds always have a SPL (sound pressure level) greater than 0 (otherwise they would be inaudible (subjectively “silent”).

There is no direct numerical relationship between signal level in Audacity and the loudness of the sound (sound pressure level), because the sound pressure level depends on how high your amplifier is turned up and the sensitivity of your headphones / speakers etc.

If you’re talking about live performances, that’s in Sound Pressure Levels or SPL. You can measure that with an SPL meter.

And yes, those values do go positive. In that example, the knob is set for 90, so “0” on the meter is +90dBSPL. That’s the one you use when you see statements like jet engine noise is some value of loudness.

A and C are “weighing.” “A” responds much like human hearing with limits on really high and really low pitch. “C” is flatter and measures almost everything,

“A” is generally called out in hazard exposure measurements and regulations.


You know what A is. That’s fingernails on blackboard and baby screaming on a jet. That’s A weighing.


Im just not getting this at all, it has no reference to any thing ells

  1. my chainsaw has 113 db marked on it
  2. this TV recording rates it at 105 db

Anyway I find the whole Audacity program far to complicated then it needs to be and It’s just not a very usable friendly program


Those markings are probably “dB SPL” (Sound Pressure Level: reference 20 micropascals).

Let’s say you recorded the chainsaw with the microphone placed 1m away from the chainsaw, and adjusted the recording level so that the sound recorded at “full scale” in Audacity.
The “signal level” in Audacity would then be “0 dB” with reference to full scale.

Now let’s say that without changing any settings, you move the chainsaw 1 km away from the microphone, and record again.
Obviously the recording level in Audacity is going to be tiny.

Now let’s say that you bring the chainsaw back up to 1 m from the microphone, but turn down the recording level to 0.1. Again the signal level in the recording will be low.
In all cases, the “sound pressure level” of the chainsaw is the same, but the recording level varies depending on lots of things, including the recording settings, the sensitivity of the microphone, the distance between the microphone and the sound source …

Regardless of the simplicity or complexity of the program, physical properties remain the same - there is no direct correlation between signal level and sound pressure level.

I find the whole Audacity program far to complicated then it needs to be and It’s just not a very usable friendly program

You should probably find a different program.


You see to 9 out of say 10 people who use this program will most probably not be sound engineers (like myself)
So can you tell me if it is posible for the sound meter to messure "db spl 20 micropascals (of say) 100 db or not?

When I first looked, all I wanted is something simple; that would allows me to record my voice over a backing track. I looked online and found nothing even as simple as this easy to find. Audacity was the only option. Although when I first started using the program it was a lot more complicated back then even trying to save a file (render and import mp3 stuff). But now it is a lot more easyer to use but it is still a long way off from todays standards of plug and play

it is still a long way off from todays standards of plug and play

True, but we also have many users that need good technical sound editing and services that can match other programs, and we only have enough developers to make one program.

So can you tell me if it is posible for the sound meter to messure "db spl 20 micropascals (of say) 100 db or not?

You can make a sound meter like mine do that. It’s no longer available with the collapse of Radio Shack.

You can’t easily cross between the sound pressure readings in the air and the digital sound readings inside the computer. That’s the hard part.

Are you trying to work around legal regulations for high volume hazards? Those all require an A reading SPL meter. You can’t do it in Audacity.


In Audacity you can measure the level of the “signal”.

How big that signal is in relation to the “sound” depends on many factors, including microphone sensitivity, microphone placement (microphones are often directional), how much the sound card amplifies the microphone signal, and your recording settings. A program running on your computer (any program, not just Audacity) has no idea what sort of microphone you are using, whether or not it is directional, how much amplification the microphone pre-amp is applying, or anything that is external to the software.

So there is no way for any software to directly measure sound pressure level.

To measure sound pressure level with software, you need to have a calibrated system, where the characteristics of the microphone, pre-amp and settings are known to the software.

Or, oddly…