Re: Timing Comparison?
"David McClain (as dbm at refined-audiometrics dot com)" <[email protected]>
| Newsgroups | gmane.lisp.lispworks.general |
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| Message-ID | <[email protected]> |
More or less correct… we don’t suppress anything. But we measure the incoming sound in Bark channels (you were correct on that count), and we apply nonlinear compression to each channel in varying degrees according to the depth of your impairment. What we found is that all humans have impairment slopes that average around 3.2 dB/Bark. What varies is the degree of impairment, but not its spectral slope. This appears to be the case, and may be related to the viscosity of cochlear fluid surrounding the basilar membrane. So, once you adjust to the degree of hearing impairment at, say 4 kHz, the all other levels of impairment correction can be deduced from that degree and the known spectral slope. The (simple) equation for normal hearing is called “EarSpring” because it is just the equation of a harmonic oscillator whose stiffness term varies in proportion to the incoming RMS level of sound at that frequency. Imagine your hearing being represented by a bank of EarSprings feeding your brain. But the whole of human hearing is the closed loop system: Outer ear, middle ear, cochlea, afferent 8th nerve, brain, efferent 8th nerve. The inner hair cells of the cochlea are the pickup, and the outer hair cells are the feedback stiffness control to prevent runaway damaging levels of oscillation of the basilar membrane. As a result our hearing at normal everyday sound levels exhibits a cube-root compression, so that we can accommodate sound levels from whisper quiet to roaring jet engine loud. > On Nov 3, 2025, at 06:29, Yuri Davidovsky <[email protected]> wrote: > > > >> On 3 Nov 2025, at 14:17, David McClain <[email protected]> wrote: >> >> I don’t know if this writeup will make it through this thread or not, but here is my most recent technical paper on how everything works: > > I will give it a read. So what exactly do you mean by describing the human hearing by equations, you figured out how Bark channels get anchored to specific frequencies? The nature of the correction is that you find suppressed frequency channels and try to compensate for them specifically? _______________________________________________ Lisp Hug - the mailing list for LispWorks users [email protected] http://www.lispworks.com/support/lisp-hug.html