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Humans and animals have different hearing ranges. The frequency range of a human, for example, is stated with 20 Hz to 20 kHz, whereas the fundamental voice frequency is stated with 125 Hz for men, 250 for women and 440 for children.

Now if I understand correctly, the hearing range of bats, for example, is commonly stated with 1 kHz to 200 kHz (depending on species). The hearing range of mice is stated with 1 kHz to 70 kHz.

Are there (apart from those with no sense of hearing at all) any animals that are unable to hear human voices at all?

(Edited in reaction to the first and the second comment below. Humans can obviously realise speech with energy at much higher frequencies. My examples are in this respect misleading.)

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    $\begingroup$ In your background information you may be misinterpreting the meaning of fundamental frequency; human speech includes substantial energy at much higher frequencies than the ones you mention, centered around about 1 kHz on a log scale. $\endgroup$ – Bryan Krause Feb 24 at 18:14
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    $\begingroup$ There are plenty of animals that don't have a sense of hearing. E.g. I don't think sponges or jellyfish have a sense of hearing $\endgroup$ – Remi.b Feb 24 at 18:29
  • $\begingroup$ Thank you, Mr Krause, for your remark. I have indeed misinterpreted the meaning of fundamental frequency and insofar given misleading examples. I do realise that humans are able to realise speech at much higher frequencies than at fundamental level. My original question, however, if there are animals that do have a sense of hearing and yet are unable to hear the human voice, remains. Thank you, $\endgroup$ – Tausendsassa Feb 24 at 18:41
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Are there (apart from those with no sense of hearing at all) any animals that are unable to hear human voices at all?

I don't know of any examples off the top of my head, but let's think about this systematically.

The voiced speech of a typical adult male will have a fundamental frequency from 85 to 180 Hz, and that of a typical adult female from 165 to 255 Hz.

These are fundamental tones, and DO NOT include overtones (harmonics) of higher frequencies, that are actually responsible for the timbre of the voice, i.e. its characteristic sound and full content sonic content.

Here is a Fourier transformation of an audio clip of a female voice (a plot of frequency vs. amplitude, whereby the original recording was broken down into its constituent sine waves).

enter image description here

As you can see, the vocal cords produce overtones up to - and beyond - 7.5kHz. These overtones theoretically go to infinity in frequency, but are very negligibly quiet past around 10kHz in our case. Certainly very low in terms of decibels (though do not confuse real decibels with the -70dB sensitivity on the graph; with audio processing gear, 0dB is at which the signal is maximally saturated, or 'clips'). Let's assume 10kHz is the upper limit for normal female speech.

Keep in mind this does NOT mean that one could not perhaps sing a high note, and produce overtones past 10kHz - this is in fact doable. But let's stick with regular speech in our case.

Below you'll find the hearing ranges of some animals (source). enter image description here

You'll find that all animals listed (save one) can hear some significant range of a regular (female) human voice. The little brown bat would not be able to hear the upper harmonics of a typical female speaker, given that they speak in a monotone.

Lastly, please keep in mind the difference between decibels ('loudness') and frequency (ability to sense a pitch). Some of the extreme high overtones are very quiet, so even if an animal would be able to sense them, they may not have a sensitive enough ear to pick up how quiet these sounds would be.

And really lastly, remember that sound produces vibrations and resonates through objects that sound waves hit. These resonate at different frequencies, so your voice can be sensed indirectly too through these resonating frequencies.

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    $\begingroup$ I hate to upvote an answer to what I consider a poor question, but I congratulate you on the evidence you have brought to bear on this. $\endgroup$ – David Feb 25 at 20:27

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