Any suggestions would be welcomed. Eventually I would love to be able to control it programmable
You may want to search for an AWG (Arbitrary Waveform Generator). Almost any AWG can go from 0 Hz (DC) to many MHz, which will cover the range you are interested. Siglent and Rigol are trustworthy brands yet not very expensive, and they have many models less than $1000.
Modern lab instruments (like e.g. an AWG, oscilloscope, power supply, etc.) can be controlled remotely by SCPI (Standard Commands for Programmable Instruments). Instruments marked as LXI (LAN-based eXtensions for Instrumentation) can receive commands by LAN (Local Area Network). Older/second hand would usually have GPIB (General Purpose Interface Bus) instead of LXI.
Sure you can try to build a generator in many ways. How easy/cheap/time consuming would be depends of the signal you need and the skills + time you want to put in it. If you can afford a generator, either new or second-hand, I would rather buy a generic one than one build a dedicated one.
If you define very well what signal you need, a microcontroller (or maybe just a soundcard followed by a mixer, or by a PLL (Phase-locked loop) at its output might be enough.
For the sound/ultrasound producing part, meaning amplifiers and electro-acustic transducers, that's another story. Can be many ways, you need to define what you want to achieve (put some specs and numbers), or tell what you want to study, such that people can point to relevant ways of doing that.
You need to specify what you mean by tone generator!
Do you mean a sinewave oscillator, or would you prefer a squarewave or some other waveform?
for about 6$ you can make this awg from this instructable: https://www.instructables.com/Arbitrary-Wave-Generator-With-the-Raspberry-Pi-Pic/
i built it and designed a simple 3 transistor amplifier for it, and in the end it was like 20$ for everything, and fairly usable for the cost. i think it's the simplest to build yourself, and maybe also even the cheapest.
As I do not know the particular waveform required to achieve the desired outcome. I only know the most likely frequency range theorized to produce certain effects.
The DDS route is ideal. I'd save myself the bother and search ebay or aliexpress for "DDS 1HZ-500KHz Function Signal Generator Sine Square Triangle Wave Frequency" 3 bucks, whats not to love? You may need a buffer/ power amp to drive your transducer.
As I do not know the particular waveform required to achieve the desired outcome. I only know the most likely frequency range theorized to produce certain effects.Lets not play guessing games. Give us the overview of the application and the 'effects' you are hoping for, and we'll be able to suggest what sort of signal source you probably need and how to amplify its output to whatever levels you require. There's almost certainly a user here with relevant experience!
I hope the following is irrelevant:
Unfortunately if your desired outcome involves 'free energy', or 'over-unity', or high efficiency far field wireless power transmission, or reactionless propulsion, and similar subjects contrary to the laws of physics as generally known*, we may get a little sarcastic, but if you promise you will conduct your experiments scientifically and report your results (including negative ones) honestly, we'll promise to help with apparatus design, unless we believe its a serious risk to your health and safety, and restrain ourselves to pointing out flaws in your experimental setup and your understanding of the underlying physics that may be giving you bogus positive results.
* As electromagnetism has been a major research field for over 200 years, there's very little 'low hanging fruit' left to investigate within the capabilities and budget of a garage inventor.
First, I am aware I cannot hear these tones and I do not intend to listen to them this is for experimental research purposes. That said, I wish to be able to create these tones individually like on old analog tone generators or from digital input fed to something like that of a piezoelectric speaker but my understanding of these devices is lacking. I do have some component level soldering background and an old O-scope but its been more than 20 years since using them That said, Any suggestions would be welcomed. Eventually I would love to be able to control it programmable with something like Arduino or RaspberryPi but that would be future evolved versions. The later version might actually be easier for me as I am a career computer programmer. I understand there is a lot to this request, I do not ask every detail unless you wish to spend the time, but from a high level I should be able to work my way there. Thanks
this is for experimental research purposes
Cheap & ready made?? What's not to love! Although I imagine being of cheap Chinese manufacturing techniques the tolerances listed are likely best-case scenarios but should be ok for a start.