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36

Yes, we can. By means of bone conduction we can hear up to 50 kHz, and values up to 150 kHz have been reported in the young (Pumphrey, 1950). However, it is indeed generally agreed that 20 kHz is the upper acoustical hearing limit through air conduction. The reason for this is debated, but the transfer function of the middle ear ossicle chain is a suspected ...


7

Some moth actually do use clicks for their own echolocation: "Noctuid moths (Noctuidae) are the only group of invertebrates for whom echolocation was demonstrated": Lapshin & Vorontsov 1998 Lapshin et al 1994.


7

If all the processes through which a signal passes are linear, then it makes sense to speak in terms of a maximum useful-content frequency. If a signal passes through non-linear stages, however, it is possible that frequency content which would in and of itself be above the range of hearing, may interact with other frequency content which is also above that ...


2

Taken from "24/192 Music Downloads... and why they make no sense": Sampling rate and the audible spectrum I'm sure you've heard this many, many times: The human hearing range spans 20Hz to 20kHz. It's important to know how researchers arrive at those specific numbers. First, we measure the 'absolute threshold of hearing' across the entire ...


2

Ultrasound is considered a safe procedure (reference) which is accepted by the WHO as well (reference). There have been studies however, that show the link of ultrasound treatment to some undesirable traits. Ultrasound could be possibly linked to a decrease in body weight on birth of infants (reference). Frequent use of ultrasound may influence babies ...


2

As others have indicated, I also haven't seen direct evidence of echolocation in insects. However, there is much evidence that the auditory system of e.g. moths can hear ultrasound generated by bats (Waters, 2003). According to Waters (2003) moths mainly use this to avoid predation. The review also contain many useful references and examples of moth ...


1

As far as I can tell, the answer is no. It's hard to prove a negative so the best I can do is that none of the articles in the literature I've been able to comb through have any mention of invertebrates at all. What I can give you is that some moths use clicks to jam bat echolocation and some fish are sensitive to echolocation, "raising the possibility ...


1

I'm going to post a quick answer here, really a thought piece. Usually to detect a sound wave you need a sounding board about the wavelength of the sound. Bacteria are on the order of a few microns in length. Ultrasound frequencies range from 2 to 200 MHz (and up I assume). To have a wavelength on the order of 3 microns, a 100 MHz wave would be ...


1

Coronary artery disease thickens the wall. Flow is dramatically affected by thickness (radius to the fourth power). In an echo you observe the heart muscle i.e. does it contract normally using the surrounding muscle and baseline as a comparison. If the wall is thickened, this will cause a decrease in perfusion which will result in the heart muscle ...


1

No, echocardiography is not sensitive enough to do so. For tracing coronary arteries directly flow angiography is the choice.



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