Acoustic amplifier for those who hear differently

acctr wrote:

that the insect would fall into the bat's mouth.

And here is an interesting fact unrelated to the topic, but related to bats. They more often catch insects with their "hand" than with their muzzle.

Here he looks like he is using his "cape" .

Well, because he has fingers on his elbow .

acctr wrote:

bratHanki wrote:

If you are standing next to someone talking can you only hear them when you are in front or when you are standing next to or even behind them?.

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And how are you supposed to hear? only straight ahead? why not sideways? this is anatomy and drawing conclusions about the nature of sound based on it is a bit infantile.

Well, that's right, I hear sideways because there's something to hear on the sides too, because that's the nature of sound wave propagation in the low ranges. The example with netcopters is not quite right because they locate their prey by ultrasound and these are eminently directional. The lower the frequency, the more difficult it is to locate the sound source, which is why music systems have a common bass channel that can be placed anywhere and why satellites reproducing midrange and treble should be positioned at specific locations in relation to the listener because, thanks to the physiology of our hearing, we are able to accurately locate sound sources at higher frequencies.
Adult males have an average fundamental frequency of around 120 Hz, while adult females have an average of around 210 Hz, a range that is not particularly directional, meaning that two microphones placed next to each other, no matter at what angle, will pick up almost the same signal.
Two years ago I had my hearing tested. The audiologist was surprised that, at 64 years of age, I could still hear 12-13 kHz. So she checked me on the bone and, to her surprise, I repeated the result.

Hello
I would approach this from a different angle, this circuit is like from the time of Janusz Wojciechowski, that is from the 1960s.
First of all, I would do it on an operational amplifier, preferably quadruple, necessarily R2R, because all designs like TL082 with power supply from a single Lion cell can be put between the fairy tales.
For example, something from the MCP6042 or 6044 series, resting current 600nA (nanoamperage), supplying 1.2V to 6V, bandwidth up to 14kHz is completely sufficient for such instruments.
With the relatively high efficiency of today's headphones, you can plug directly into the amplifier output without additional terminal transistors.
With four amplifiers, you may be tempted to use frequency correction and/or tone mapping.
Regards

PiotrPitucha wrote:

the bandwidth up to 14kHz is quite sufficient for such instruments.

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Well when not, at a gain of 10 such an amplifier will have ~1.5khz bandwidth:( this is far too low.
Better would be MCP6L04T, it has admittedly higher current because 85uA but also 1Mhz bandwidth, and it is definitely cheaper because it doesn't cost 12 zł only 3 and the same has power supply 2.7 to 6V.
https://www.tme.eu/pl/details/mcp6l04t-e_sl/wzmacniacze-operacyjne-smd/microchip-technology/
But in general you are right, compression and filters are needed and this is hard to do without an opamp.

@ PiotrPitucha .
Your proposal is thoroughly modern and undoubtedly achieves excellent performance, but it has several drawbacks.

1. lack of a diagram
2. the need to purchase new parts to make the device
3. no demonstration of a working and tested device.

Maybe if I had one of the circuits you mentioned, I would be tempted to try to make such a device, but I find it more appealing to make things based on elements I have at hand (usually recycled ones), which greatly reduces the time of production and probably costs as well.
Instead of buying something new, I can make a circuit giving a "second life" to working components doomed to extinction.

Maybe one of my colleagues, who is not satisfied with the presented construction, will make and present an amplifier based on your rather imprecise description.

I suppose that in some time some tube enthusiast will propose a tube-based design. And good, because maybe it will inspire someone .

Hello
An amplifier like an amplifier, you can try it on any operational amplifier, amplifiers on operational amplifiers work as simple as voltage dividers only instead of dividing they amplify the signal.
I could cite dozens of solutions, but they all boil down to one solution, like this one for example:
Link .
The only difference is in the circuit I was proposing because you can feed it with a lower voltage.
Compressors unless they are made on dedicated circuits also have a similar design, the rectified voltage from the output controls a component that limits the voltage coming from the microphone, for example:
Link ]
By connecting such blocks together, we can build circuits with a gain tailored to the specific microphone and headphones you have.
The circuit can be simulated in any analysis software, although with operational amplifiers, the amplification can be seen on the schematic as if on the palm of your hand.
So that you don't have to bother, there are ready-made circuits that take care of compression , noise gates, etc. For example:
Link
Greetings

Added after 17 [minutes]:

Hello
Janusz_kk with the bandwidth you are right, I gave the amplifier as an example of an R2R amplifier with a low supply voltage, I myself used the MCP607 for similar purposes, which in addition has excellent DC performance.

PiotrPitucha wrote:

To take the headache out of it, there are ready-made circuits that take care of compression, noise gates, etc. , for example:
Link

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And that's it, one small cube and it takes care of the whole thing, only the headphone amp and the filter are missing, something really needs to be done here.