Talk:Hearing range

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Article revision[edit]

I can contribute the following text, which is modified and expanded from my page on testing the hearing of whales and dolphins. I'd like to get a little feedback before simply replacing the current text. I think the current text is problematic in several ways.

An audiogram is a graphical representation of how sensitive a subject is to acoustic stimuli across a range of frequencies. Frequency is placed on the X axis, usually with a logarithmic scale, and threshold values, usually in decibels, are plotted on the Y axis. For a behavioral audiogram, researchers obtain the needed threshold values by training subjects to respond to test tones with a specific behavior, which allows the tester to determine which tones have been heard and which were not heard (but see detection theory). For most humans, this may be accomplished by asking them to press a button or speak a word when they hear a test tone. From repeated trials, researchers estimate the threshold of hearing at each test frequency. Researchers do the same for a number of frequencies of test tones to find the audiogram of the subject.

For a behavioral audiogram, the subject is trained to make a response to an acoustic stimulus. The acoustic stimuli are given at many different frequencies and amplitudes, and an estimate is made of the threshold of hearing for each frequency. This approach contrasts with audiograms taken using electronics to pick up the faint signals of the brain's response to those stimuli, or neurophysiological audiograms. A common approach to obtain a neurophysiological audiogram is to monitor the auditory brainstem response (ABR).[1] While a neurophysiological audiogram by ABR has the advantage of not being dependent on having trained subjects, it has the disadvantage of requiring even more sophisticated equipment and impeccable technique in order to carry it off. Also, neurophysiological and behavioral audiograms do not usually agree precisely, even when taken on the same subject. A neurophysiological audiogram tends to indicate several decibels better sensitivity across the tested frequencies than does a behavioral audiogram.

A neurophysiological method for human subjects that is not as precise as ABR, but which can be accomplished with less complex equipment, relies upon otoacoustic emission. The healthy human ear not only transduces received sound energy, but also produces evoked otoacoustic emission of sound in response to acoustic stimuli. A small microphone placed in the external ear canal can pick up these small signals and indicate that the ear can react to a particular stimulus, or indicate a hearing deficit if no response occurs to a normally audible test tone. Such a technique is useful for constructing an audiogram of a human subject who cannot complete a behavioral audiogram, as in severe cases of autism.

As anthropogenic noise becomes more widespread, concerns about impacts of noise on animal populations grows. Audiograms for species become important tools for researchers and policy makers to take into account when dealing with anthropogenic noise. Unfortunately, relatively few species of birds or marine mammals have had audiograms constructed for them. For example, there is no audiogram of any type available for any mysticete cetacean.[2]

A problem with audiograms of non-human subjects is that there is often a tendency to use an audiogram obtained from a single subject and treat that as a representative audiogram for an entire species. This famously led to many years of confusion, from 1972 to 1999, as researchers believed that killer whales could not hear frequencies above about 32 kilohertz, based upon an audiogram of one subject. Later, audiograms taken on other killer whales revealed that their hearing was similar to that of other odontocete cetaceans, with ultrasound sensitivity up to about 120 kilohertz, indicating that the original subject had extensive high-frequency hearing loss.Szymanski et al. 1999

Another issue concerns the completeness of testing for an audiogram. For decades, shad were considered to have an ordinary audiogram for fish, with peak sensitivity under 1 kHz and an upper limit of hearing between 1 and 2 kHz. Further testing, however, demonstrated that shad actually could detect ultrasonic sound up to about 180 kHz.[3]

Wesley R. Elsberry 08:07, 12 April 2006 (UTC)

The above was copied from Audiogram when the animal content of that page was moved here. I think this is very useful, but not strictly audiometry as it relates to absolute not relative measurement. --15:52, 5 March 2008 (UTC)

Contradicting Information[edit]

I know wikipedia is not the best source for "reliable" information (or at least, that is what is drilled into our minds every time we consider using it as a resource), but I am trying to discover information relating to the maximum hearing range of dogs (and to a lesser extent, humans). Unfortunatly, the image provided (the dark coloured bar graph(?) with numerous animals's hearing ranges) contradicts the text information, citing a maximum hearing range of 23kHz for humans (20kHz in the text, and most other resources) and 45kHz for Dogs (60kHz in the text, and little information given in other resources). Clarification on this information or links to more recent or non-conflicting sources would be appreciated. Thanks, Jonzay (AKA --203.214.151.1 (talk) 12:50, 20 May 2008 (UTC))

After a year it appears this hasn't been resolved. Human range in the article is 16-16384hz (the high number looks suspect even by itself; 5 signifigant figures but the low measurement is only 2 signifigant figures? and it so happens to be EXACTLY a power of 2?), but the graph gives a much different 64-23000hz. Anyone know what's up? 69.255.248.13 (talk) 00:09, 21 June 2009 (UTC)
Both the text and the bar graph are incorrect. The text contradicts the bar graphs at several places and for several species. In fact, human hearing is beyond the range in the text. 16 Hz is generally accepted as the low frequency detectable by the human ear. 16 KHz is much too low for the upper range. 20 KHz is given because it is generally the high frequency limit of speakers, but humans have shown teh ability to hear frequencies as high as 21 KHz, though this is rare. Whether higher frequencies are detectable and whether resultant frequencies or increased amplitude due to these resultant frequencies, are detectable is still debated. Marchesa (talk) 06:12, 14 July 2009 (UTC)
The range of human hearing varies between individuals depending on many factors including age, sex, and ethnic background (various genetic variations passed on which cause variations in hearing structure size, shape, sensory distribution, neuronal sensitivity, etc.; all of which have an impact on the hearing range of the individual). Some individuals can hear very low or high ranges which others never had any sensitivity to. Many of the numbers in the article seem to be generalizations (which is appropriate) however, there should be indication that: a) these are general/average ranges; b) what the known extremes tend and/or are known to be. With the advent of digital music, individuals with out-of-the-general range hearing have been easier to find as those with higher ranges are more prone to indicate they hear digital artifacts in the reproduced audio (such as music that has been 128b mpeg3 encoded which is good sound for general human hearing, but leaves many "chirping" sounds in it which higher range listeners can hear, but are mostly unheard by these individuals with 192b mpeg3 encoding). Someone with good citations should make adjustments to this article. —Preceding unsigned comment added by 71.196.135.148 (talk) 20:10, 26 November 2009 (UTC)

I grant Wikipedia as the most trustworthy source of information insofar, and I have strong proof for this. So the "reliability" issue is not an issue. I found this: Cats[edit] [...] while humans can only hear from 31 Hz up to 18 kHz, and dogs hear from 67 Hz to 44 kHz [...] Dogs[edit] [...] though the range of hearing is usually around 40 Hz to 60 kHz (60,000 Hz) [...] Please reconcile. — Preceding unsigned comment added by 188.27.182.142 (talk) 18:22, 21 November 2013 (UTC)

Insects, etc. animals, and even plants[edit]

Make sure to mention each major type of animal, e.g., crickets obviously are chirping for their compatriots to hear.

Even mention plants: do some species do bad near (what frequencies of) noise? Jidanni (talk) 20:03, 18 June 2008 (UTC)

Mice Hearing Range[edit]

Can someone clarify the section discussing the hearing range of mice. It first says that the low end is at 1KHz (which is quite a bit lower than the given human range listed above it) but almost immediately continues by saying that mice can not hear the lower frequencies that humans do. As I read it now, this looks like a contradiction. The only way that I can see how this would not be contradictory is (and this is quite a stretch of trying to force a non-contradictory situation) if mice were to have sensitivity to ranges below human hearing, but then lose sensitivity in the range of the lower human frequencies, but then the mice sensitivity picks back up. However, this would seem to me as very unlikely, and IF this were the case, this should be indicated with citation. At the moment, I would guess someone goofed up when they wrote the second statement. —Preceding unsigned comment added by 71.196.135.148 (talk) 20:16, 26 November 2009 (UTC)

The above misunderstanding comes from a misreading of the units of frequency. The article is clear enough. Μάριος Ζηντίλης (talk) 18:54, 4 February 2012 (UTC)

Earshot?[edit]

Shouldn't Earshot redirect here (or at least have a "were you looking for" thing at the top)? I know I, at least, expected to find one when I went there. 76.191.19.65 (talk) 06:49, 9 October 2011 (UTC)

Oh, wait, RTFA - this isn't quite what I thought it was. 76.191.19.65 (talk) 06:50, 9 October 2011 (UTC)


Impact human generated waves and nuisance for animal hearing range ?[edit]

I'm one of the environmental judges at the Brussels Capital District. We have many cases on the impact of gsm's/mobile phones/wimax technologies and Natura 2000 sites. Anybody has any knowledge about nuisance between e.g. gsm etc. frequencies and pillars put in Natura 2000 sites - roads passing such sites - and e.g. interference with e.g. frequencies used by bats, in that bats would e.g. stay away from gsm pillars as these bats or other animals can't "see" there anymore?

I assume not as soundwaves are pressure waves and gsm waves are electromagnetic waves and I assume an EM wave doesn't cause a pressure wave, i.e. an audible wave. But can an EM wave make a little hearing hair vibrate and thus make it audible? Moreover, bats hear in the kHz range and mobile phones are in the MHz range.

"Bats ... hearing range varies by species; at the lowest it can be 1 kHz for some species and for other species the highest reaches up to 200 kHz. Bats that can detect 200 kHz cannot hear very well below 10 kHz.[8] In any case, the most sensitive range of bat hearing is narrower: about 15 kHz to 90 kHz."

From http://en.wikipedia.org/wiki/Insect#Sound_production_and_hearing :"Mosquitoes have been found to hear up to 2 MHz., and some grasshoppers can hear up to 50 MHz." Quote from GSM frequency bands: the ranges goes from 380.2 to 2.100 MHz.

Thy. --SvenAERTS (talk) 15:14, 15 April 2013 (UTC)

Audogram[edit]

The article clearly states that normal human hearing is given as 20 Hz to 20 kHz. There is an audiograph with a caption that implies it describes normal human hearing, but it is limited to representing a range of 125 Hz to around 10 kHz (if I read the scale right, with the edge dots disconnected as though irrelevant). This is inconsistent with the article and leads to confusion: is the graph/caption right that it is typical to have absolutely no hearing below 125 Hz or above c. 10 kHz? or is the body right that it is normal to be able to hear both higher and lower sounds? (This is, indeed, why I went around to check what exactly this graph was showing, because it certainly wasn't showing what it said it was showing.)

The article on audiograms states:

Most audiograms cover a limited range of frequencies 100 Hz to 8000 Hz (8 kHz) because this range includes the fundamental frequency of sounds in speech.

But it does not cite it either. Would you like to remove the equivalent comment there?

Perhaps the graph is misplaced here, and some other image, or none, would be better.

Run to the hills, cos the end of the world is soon! (talk) 06:55, 4 May 2014 (UTC)

Perhaps the discrepancy is due the 20-20kHz range being based on un-naturally isolated frequencies at un-naturally loud levels (but scientifically, it is true to say that these frequencies can be heard), but standard hearing tests stick to those frequencies that occur in significant amounts, and with not insignificant effect, more naturally. Need to find a source that would allow the main text to be augmented along these lines.—Aquegg (talk) 08:35, 4 May 2014 (UTC)
That is certainly one possible speculation, although I don't find searches for affirmative evidence a particularly good approach. In any case, the article contraconfirms it already, allow me quote:
Humans have a maximum aural range that begins as low as 12 Hz under ideal laboratory conditions,[4] to 20 kHz[note 1] in most children and some adults.
with note 1 being quite explicit:
20 Hz is considered the normal lower frequency limit of human hearing. When pure sine waves are reproduced under ideal conditions and at very high volume, a human listener will be able to identify tones as low as 12 Hz.
When you've found your citation, you'll need to make many appropriate modifications to the existing text.
Sounds with higher frequencies occur quite commonly naturally, from students ring tones to (old) TVs and fluro lights to (apparently, if the article is to be believed) mouse squeaks.
A hearing test, though, is only going to be testing for frequencies that are useful to modern humans (and not the annoying ones): namely, those that are useful for human speech.
Incidentally, if it please you, I can offer this quote from an old textbook:
Previous research on the acoustic phonetic descriptions of speech sounds suggests that they do not have significant amounts of information in frequencies above 10 kHz. Consequently, a sampling rate of about 20 kHz is adequate for recording speech sounds. Evidently the stereo-maker choice to design an audio system for "young healthy" ears is overkill for speech communication... As we shall see in the next chapter, frequency components above 10 kHz are not likely to be useful for speech communication even if the listener has perfect hearing, because human sensitivity to frequency information above 10 kHz is rather limited. Keith Johnson (2003). Acoustic and auditory phonetics (2nd ed), pp. 22-23. Malden, MA, US: Blackwell.
It certainly is not related to audiogram ranges, but it does once more suggest that it is the utility, not the availability, of sounds outside of the range in the tonogram that is defining the range.
Run to the hills, cos the end of the world is soon! (talk) 11:31, 4 May 2014 (UTC)
I removed your addition since there was the possible implication that standard hearing tests are in some way lacking; they might well be, but if that is the case, we should cite it from a reliable source. Watch-words here are "Note that ...": this is often a sign of editor opinion/emphasis that may not be present in the source. I don't see the current situation as blatant contradiction, since the graph does not purport to make a statement on the upper limit of hearing (under any particular conditions) or the significance of higher frequencies in any specific circumstance. I agree that the article (as most) could probably do with a lot of clean up, but I'm not necessarily volunteering to do it all! "Important to speech" sounds dubious to me—most folk need to be able to hear things other than speech: doorbells ringing, oncoming vehicles, etc.; but of course, what we need here is good refs. I did a quick search for something that might help clarify the text but have not found anything obviously useful so far, I'm afraid.—Aquegg (talk) 13:13, 4 May 2014 (UTC)
Update: I've added a cite for "Humans are most sensitive to frequencies between 2000 and 5000 Hz". This, I think goes some way towards explaining the restricted range of hearing tests. Other reasons include (but not currently mentioned): there is less energy at the sound source in harmonics than in fundamentals, and high frequencies propagate less well through air, so their energy is further reduced by the time they reach your ear.—Aquegg (talk) 21:09, 4 May 2014 (UTC)