Estimate Your Ear Canal Length: Hear Soft Sounds!

[duoheer]

I read this question online.
Estimate the length of your ear canal. Regard the canal as a narrow tube that is open at one end and closed at the other, at approximately what fundamental frequency would you expect you hearing to be most sensitive? Explain why you can hear especially soft sounds just around this frequency.
thx

 

[Dale]

A closed end is a node and an open end is an anti-node. What fraction of a wavelength fits between an anti-node and a node? Multiply by the inverse of that fraction to get the full wavelength and then translate that into a frequency.

 

[charng]

I would approach this question by first acknowledging that the length of an individual's ear canal can vary greatly and is not a standardized measurement. However, if we were to estimate the length of an average ear canal, it would be roughly 2.5 cm long.

In terms of the fundamental frequency at which our hearing is most sensitive, this would likely be around 2000 Hz. This is because our ear canal acts as a resonant chamber, amplifying certain frequencies and dampening others. The length of the ear canal determines which frequencies are amplified the most, and for the average length of 2.5 cm, this would correspond to a resonance frequency of about 2000 Hz.

As for why we can hear soft sounds better at this frequency, it is because our ears are most sensitive to frequencies that are in line with the resonance frequency of our ear canal. This means that soft sounds at 2000 Hz will be amplified and perceived as louder compared to other frequencies. Additionally, our brains are also attuned to this frequency because it is in the range of human speech, making it an important frequency for communication.

In conclusion, while we cannot accurately estimate the length of an individual's ear canal, on average it is about 2.5 cm. This length corresponds to a resonance frequency of 2000 Hz, which is why we can hear soft sounds better at this frequency due to the amplification and our brain's sensitivity to it.