Talk:Critical band

Misleading Figure
The figure showing the tonotopic map of frequencies along the basilar membrane (https://en.wikipedia.org/wiki/Critical_band#/media/File:Basilarmembrane2_topath.svg) is misleading, given that the figure shows a wider basilar membrane in the base than in the apex, while in fact it is the opposite. It could not be as the figure shows, given that the apex is located in the thinner part of the cochlea. — Preceding unsigned comment added by 186.135.37.58 (talk • contribs)

Or not. — Preceding unsigned comment added by 95.5.67.105 (talk) 20:44, 6 March 2016 (UTC)


 * The figure does not show what you say. It is correct.  Perhaps you think the BM should be narrower near the apex?  In fact, the cochlear partition does go from wider near the base to narrower near the apex, but the BM, the main part that moves, is a small part of the partition near the base and a larger part near the apex, and goes from narrow near the base to wider near the apex.  Dicklyon (talk) 21:58, 6 March 2016 (UTC)

Specific numbers
The article on the Bark scale quotes a set of numbers a being the "edges" of the critical bands. Would this not be a more appropriate place for that listing? yoyo 07:50, 17 March 2006 (UTC)

Musical implications
I'd like to have some information on what the existence of critical bands implies for the theory and practice of musical composition. yoyo 07:50, 17 March 2006 (UTC)


 * Probably no implications. Given that most theorists are comfortable with overlapping bands and/or bands at any given frequency, they can't really have that sort of impact.  169.234.128.51 (talk) 03:13, 27 August 2009 (UTC)


 * Some implications. Tones within a critical band but out of sync tend to sound dissonant, whereas tones separated by more than a critical don't.  Considering harmonics, it gets more complicated, but this is one relevant effect, which makes small intervals dissonant.  Dicklyon (talk) 03:17, 27 August 2009 (UTC)


 * Definitly some implications! The following article supports the above comment by Dicklyon: PLOMP, R. and LEVELT, W. J. M., "Tonal consonance and critical bandwidth", Journal of the Acoustical Society of America, vol. 38, pp. 548-60. Philfrei (talk) 06:57, 26 January 2010 (UTC)

Wrong formula
ERB in hertz is calculated this way: ERB = 24.7*(4.37F + 1) Note that the formula for the ERB-rate (in ERB units!) looks quite similar: r_ERB = 21.4*log10(4.37F + 1) Reference: B. Moore: Psychology of Hearing, 4th Ed., Academic Press, 1998, pp. 109-110. — Preceding unsigned comment added by 194.39.218.10 (talk • contribs)


 * Probably obsolete comment by now; see subsequent sections. Dicklyon (talk) 22:08, 6 March 2016 (UTC)

Out of date - please help improve
The claim "The auditory system is thought to contain an array of over-lapping band-pass filters known as ‘auditory filters’" together with a reference from 1940 is hopelessly out of date. Overlapping bandpass filters can only ever be a crude approximation of the response of the basilar membrane and the auditory system overall. I will try and improve this section somewhat but please help! --mcld (talk) 14:39, 16 June 2009 (UTC)

ERB equation incorrect
The equation ERB = 21.4*log(4.37*f/1000 +1) does not agree with the values shown in figure 2.

According to an article at CCRMA (https://ccrma.stanford.edu/~jos/bbt/Equivalent_Rectangular_Bandwidth.html), the equation above stands for ERBS. ERBS is "The ERB scale is defined as the number of ERBs below each frequency", and is not the ERB value.

CCRMA references B. C. J. Moore and B. R. Glasberg, ``A revision of Zwicker's loudness model,'' Acta Acustica, vol. 82, pp. 335-345, 1996. — Preceding unsigned comment added by 207.118.32.140 (talk) 23:34, 16 July 2011 (UTC)


 * I reverted back to the previous numbers; that's the equation for bandwidth in ERB, as it says, not the ERB scale (or ERB-rate scale) that counts ERBs. Some anon had recently changed it to the formula for the scale.  Dicklyon (talk) 18:04, 17 July 2011 (UTC)

Manifest silliness of "time taken for (sound) to travel through the cochlea."
The given number ("only 5 milliseconds") is cited as being taken from a standard text, but it means the speed of sound through the cochlea is V = total length divided by time, or very roughly 60 millimeters / 5 milliseconds = 12 meters / second (about 25 miles per hour). The speed of sound in water is over 1400 m/s, in air over 300 m/s. I can't imagine a medium so ineffective at transmitting sound as the fluid-membrane system of the inner ear! Is this 5 ms value an error, or can this startlingly slow speed at least be further explained? Randallbsmith (talk) 20:32, 31 July 2014 (UTC)


 * The travelling wave moves from base to apex but it does not have a uniform speed. The speed decreases with distance. — Preceding unsigned comment added by 186.135.37.58 (talk • contribs)


 * And yes the wave speed is quite slow; much slower than the speed of a sound wave (compression wave) in liquid. Dicklyon (talk) 22:05, 6 March 2016 (UTC)


 * How the 5ms time interval or the wave speed was measured accurately? — Preceding unsigned comment added by 123.122.51.10 (talk) 07:52, 17 November 2016 (UTC)