How could a monotone with a time-linear increasing frequency be generated?

I searched the forum with the string “variable frequency generat”. Found four posts, but their level is way beyond mine, being about programmatically generating frequencies.

I need to generate a monotone of 20 seconds, beginning from 100 Hz and ending at 108 Hz. Just a linear variation of 8 Hz in 20 seconds.

How could this be accomplished?

I use audacity for minor editing purposes only: cutting, increasing or decreasing amplitude (amplification) and noise removal. I don’t have your level of expertise. So please be gentle on me regarding your instructions.

it really sounds like you need, to write a special program, for your special need.
or… generate the 9 tones with audacity, 20s/8 long and then stitch them together.

Thank you for replying to my query.
Those aspects have been contemplated.
(1) I can’t write a program. May be if someone could write me a program could this requirement be accomplished.
(2) In case of stitching together 9 tones of 2 seconds each, the change wouldn’t be continuous but like a step ladder.
Best wishes.

im not sure, if you want a non-integer frequencies here, but if it is so, i think, this does not exist.
100-108 contains 9 values, so each tone shall be 20/9=2.(2)seconds long, which is another thing, that does not fit well into 20(integer) seconds.

Generate: Chirp … Chirp - Audacity Manual

https://en.wikipedia.org/wiki/Just_noticeable_difference#Music_production_applications

So the 8Hz change (108-100) is only just detectable by ear.

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Thank you Mr. Trebor, most importantly for the keyword “chirp”.
I was wondering: How could someone rarely visiting the manual find an association with the word “chirp” and monotone linear increasing or decreasing frequency in time? Also, if Audacity is the visual implementation of sox, then it must be able to do at least what is already possible in sox.
Yesterday, I searched SourceForge sox forum and found a solution. sox code was run on the terminal to generate a linearly increasing then decreasing monotone as follows:
`play -n synth 10 sine 200:212 sine 212:200 delay 0 10 remix 1,2 1,2 repeat 999`
And this worked well. The output was captured by the laptop’s input audio port.

I always lament that the weakest link for GNU-Linux is the forum system, even when there are many supporters like you ready to help. So much character jungle one has to meander through just in order to offer support to another fellow user!

I wish that GPT4 was implemented in the forums and help us all in finding a solution within the shortest time-frame.

But the above lines `shouldn't` in any way `reduce` the `quality of support` that you provided.

This post should also serve as a note for individuals like lx_nametooshort to not post unless assured that such a functionality doesn’t really exist. It discourages novices such as us when a functionality is needed the most and also from using GNU-Linux environment.

The rest part has been removed on the advice from the System, Audacity Team. The earlier para should be considered and steps assessed to avoid situations mentioned therein.

keep editing, you are not done yet.
you know what is funny… when i said “generate with audacity”…
have you edited, that command line you found, for your needs?

i myself am looking forward, to be wrong and corrected.
so here i am self-correcting myself, yet again… im sure now, there can be non-integer frequencies.
also that image helped me, to remember the interpolation.

my basic suggestion and the chirp generator sound the same, and work effectively, to give you a headache.
im quite curious, what is your need, for such a sound.

I agree that name “Chirp” is not very descriptive, but it goes way back to Audacity’s very early history. Originally it was designed to generate short sweeping sine waves from very low to very high frequency (that sound like a sort of “chirp”) for analytic purposes. Later, as Audacity matured, the effect was extended to provide a choice of waveforms that could sweep from any frequency to any other, but the old name stuck.

Perhaps a better name would be “Tone sweep” or “Variable Pitch Tone”, but if the name were changed now there would probably be a lot of people asking “Why has the Chirp generator been removed?”

It isn’t. Audacity and SoX are very different applications, created and developed by different teams for different purposes. There are some similarities between the two (both are open source apps used for processing audio), and Audacity does use the SoX’s resampling library (because it is arguably the best open source resampling libraries), but other than that there is not much connection between the two.

Audacity can do almost anything that SoX can do, and can do many things that SoX can’t do, but there are some things that SoX does better or that SoX can do more easily. The main advantage that SoX has over Audacity is for tasks that need to be run programmatically or from the command line. Audacity does support scripting, but for example, if you need to integrate audio processing into a fully automated workflow, then that is likely to be much easier to do with SoX.

To do that sort of task in Audacity, the best tool is to use Audacity’s built-in scripting language “Nyquist”. Nyquist scripts can be run either as plug-ins, or from the Nyquist Prompt.
An example that can be used in the Nyquist Prompt:

``````;type generate
(mult 0.8  (hzosc (pwl 0 220 5 440 10 220 10)))
``````

Dear Mr. Steve,
I have been cautioned that:

Only a short reply can do justice to your post: A sincere “Thank You” for your kind and detailed notes.

One short question:
Is there a keyword dictionary for audacity available online to list all functions and their usages exhaustively with examples?
Please consider if we are required to drag this thread on. You could suggest via a PM if you require me to begin a new thread.

That is incorrect.
The “frequency” of a tone is the “number of cycles per second”. If a tone repeats 10 times per second, then it has a fundamental frequency of 10 cycles per second, which is written as “10 Hz”. If a tone repeats once every two seconds, then it has a frequency of 0.5 Hz.

There is a glossary, but it does not cover all terms that are relevant to Audacity: Glossary - Audacity Manual

There is a list of all effects that are included in Audacity: Index of Effects, Generators, Analyzers and Tools - Audacity Manual