The title does, prima facie, appear absurd.

Performing a swallowing action whilst pinching the nostrils shut gives the impression of listening through a bucket filled with water around the head; audible sound levels are perceptibly reduced. Some humans may encounter a similar sensation blowing their nose - hard.

This makes sense give the ears connect to the mouth/nose through the eustachian tubes. Can an odour make its way to the olfactory sensors through the ears?

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    $\begingroup$ do you mean "are there olfactory receptors in the ears" or "can smelly things make their way through our ears to the nose". Cause in the second case, the eardrum is in the way. $\endgroup$ – Shep Dec 5 '12 at 21:21
  • $\begingroup$ @Shep: The latter; sometimes when i put drops in me ears, i get this weird taste too ... $\endgroup$ – Everyone Dec 6 '12 at 10:19
  • $\begingroup$ @Everyone - It doesn't take a high concentration of aromatic compounds in the air to actually stimulate a smell (or taste) response. I'd bet that enough of the drops vaporize in your local head-space that you end up tasting the stuff. Happens with me and menthol all the time. $\endgroup$ – MCM Dec 6 '12 at 12:55

A quick diagram to point out to people who may not know what Eustachian tubes are (#2).

Anatomy of the Ear

In order for the aromatic molecule to reach the olfactory bulb, it would first have to get through the Tympanic Membrane (#22) [a.k.a. - Eardrum]. The Tympanic Membrane is water/airtight unless pierced.

So, while it's plausible that an aromatic molecule could travel through the Eustachian tubes and enter the pharynx areas, there isn't any way to get into the middle-ear in the first place unless the Tympanic Membrane has been compromised.

In a healthy and intact individual, the answer should be No.

  • $\begingroup$ TY, clear, and to the point. p.s. I'm doomed )+: $\endgroup$ – Everyone Dec 6 '12 at 10:21

@MCM gave a succinct and accurate description of how a healthy and "normal" person will not be able to smell via olfactory sensing trough the Eustachian tube.

Here is an interesting concept in which the brain is able to confuse senses, or alternatively, use sensory input as a metaphor for interpretation via another sensory output. This is a condition known as synesthesia. The majority of known synesthetes have cross-talk between audio-visual sensory pathways. That is, one may interpret sounds as shapes or colours, while another may interpret specific objects (or symbols) as colours or sounds. There were a handful of synesthetes studied in the late 1980's (referred to in this article by Day S.) and one patient was able to interpret sounds as smells. In the review article, smell-interpretation of sound accounts for ~0.1% of known synesthetes, while sound-interpreting olfaction is more common at ~0.6% incidence. On some higher level, the neural information for two senses is confused, and synesthetes that may confuse smelling for some other sense, can not technically perceive scent (using olfactory receptors) through other sensory organs (like the eyes), so the answer is technically no.

  1. Day S. Psyche 1996, 2(32).
  • $\begingroup$ This blending of the senses in their perception is happening at a higher level in the cortex, though, the synesthetes are not actually smelling with their ears. $\endgroup$ – jonsca Dec 6 '12 at 3:48
  • $\begingroup$ Exactly. Just as it's impossible for eyes to perceive sound, or to smell colours. $\endgroup$ – user560 Dec 6 '12 at 3:58
  • $\begingroup$ It's a fine answer, I just thought some further clarification that it was a negative answer to the question might be helpful to the OP (but I suppose we now have it here in comments anyway). $\endgroup$ – jonsca Dec 6 '12 at 4:02

Modified 6 Dec 2012: One approach to this question is to perform a sequence similarity search for genes encoding genes with a functioning in sensing external stimuli, be they olfactory receptor, taste receptor or other such genes that are expressed in cDNAs or RNA-Seq data from library preparations of the appropriate ear tissue. While there is not likely at this point in time to be much data available in RNA-Seq format, one might find cDNA libraries from cochlea or neighboring tissue.

A "hit," meaning there is evidence that, for example, an olfactory receptor gene is expressed in cochlea, eg, only means that there is potential to smell through the ears. Taste receptors are expressed throughout the alimentary canal in humans, but tasting the contents - food or other - is not readily perceived as de facto taste outside the oral cavity. Nonetheless, there is no reason not to expect such sensors are expressed to relay information to the brain as to what is or is not present. "Smelling" in/by the ear for the purpose of detecting the presence of a given entity or molecule could serve a similar function.

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    $\begingroup$ You jumped the gun a bit. You're addressing the literal interpretation of the title, instead of the hypothetical situation addressed in the question. ;-) $\endgroup$ – MCM Dec 5 '12 at 21:42
  • $\begingroup$ And in any case, I am afraid that your data would not support your conclusion. The expression of an olfactory receptor gene in cochlea only means that an olfactory receptor gene is expressed in cochlea. It does not necessarily follow that the gene's product has the same function there as it does in the nasal canal. $\endgroup$ – terdon Dec 6 '12 at 17:36
  • $\begingroup$ @terdon I wrote that expression of a olfactory receptor means there is the potential for that function and not an absolute, defined function. $\endgroup$ – Larry_Parnell Dec 6 '12 at 18:28
  • $\begingroup$ I know, but I am a horrible pedant and have recently been working on ways of predicting protein function and this is one of my pet peeves :). To my great annoyance I cannot use expression data to infer function. $\endgroup$ – terdon Dec 7 '12 at 14:19

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