Acoustics operators
22 operators in the acoustics category of the live registry. Each is a named formula you can compose inside a state contract or call directly through POST /api/zeq/compute. KO42 is always on; add up to three more per call (total ≤ 4), per the 7-step protocol.
| Operator | Description | Equation |
|---|---|---|
AC1 | Speed of sound in a medium derived from the ratio of bulk modulus to density, corrected by Laplace for adiabatic conditions. | v = \sqrt{\frac{B}{\rho}} |
AC2 | Standing wave harmonic frequencies in a tube or string of length L, giving the nth resonant frequency from wave speed and mode number. | f_n = \frac{n v}{2L} |
AC3 | Doppler effect formula predicting the observed frequency shift when a sound source and observer are in relative motion. | f\prime = f\frac{v \pm v_o}{v \mp v_s} |
AC4 | Sound intensity from a point source decreasing with the inverse square of distance as power spreads over a spherical wavefront. | I = \frac{P}{4\pi r^2} |
AC5 | Decibel scale expressing sound intensity level as ten times the logarithm of the intensity ratio relative to the hearing threshold. | \beta = 10\log_{10}\frac{I}{I_0} |
AC6 | Beat frequency produced by the superposition of two tones with slightly different frequencies, equal to their absolute difference. | f_{beat} = |f_1 - f_2| |
AC7 | Fundamental wavelength-frequency relation linking the spatial period of a wave to its temporal frequency and propagation speed. | \lambda = \frac{v}{f} |
ACX1 | Acoustic wave equation governing pressure disturbance propagation in a homogeneous medium as a second-order partial differential equation. | \frac{\partial^2 p}{\partial t^2} = c^2\nabla^2 p |
ACX10 | Converts sound power level to sound pressure level at a given distance assuming spherical spreading from a point source. | L_p = L_w - 10\log_{10}(4\pi r^2) |
ACX11 | Fundamental resonant frequency of an open or closed pipe determined by the ratio of sound speed to twice the tube length. | f_r = \frac{c}{2L} |
ACX12 | Nth harmonic resonant frequency of a resonator, extending the fundamental mode to integer multiples for standing wave analysis. | f_n = \frac{nc}{2L} |
ACX13 | Quality factor of a resonant system defined as the center frequency divided by the half-power bandwidth, measuring resonance sharpness. | Q = \frac{f_0}{\Delta f} |
ACX14 | Stokes acoustic absorption coefficient quantifying viscous dissipation of sound energy proportional to frequency squared in a fluid medium. | \alpha = \frac{2\eta\omega^2}{3\rho c^3} |
ACX15 | Acoustic wavelength as the ratio of sound speed to frequency, giving the spatial period of a propagating sound wave. | \lambda = \frac{c}{f} |
ACX2 | Acoustic intensity expressed as the squared pressure amplitude divided by the product of medium density and sound speed. | I = \frac{p^2}{\rho c} |
ACX3 | Characteristic acoustic impedance of a medium defined as the product of its density and sound speed, governing wave transmission behavior. | Z = \rho c |
ACX4 | Acoustic reflection coefficient quantifying the fraction of incident wave energy reflected at an impedance discontinuity between two media. | R = \left(\frac{Z_2 - Z_1}{Z_2 + Z_1}\right)^2 |
ACX5 | Acoustic transmission coefficient giving the fraction of incident wave energy transmitted through an interface, complementary to reflection. | T = 1 - R = \frac{4Z_1 Z_2}{(Z_1 + Z_2)^2} |
ACX6 | Transmission loss in decibels measuring the sound attenuation through a barrier or interface from the inverse of the transmission coefficient. | TL = 10\log_{10}\frac{1}{T} |
ACX7 | Sabine reverberation time predicting how long sound persists in an enclosed space from room volume and total absorption area. | RT_{60} = \frac{0.161 V}{A} |
ACX8 | Total sound absorption area in a room computed by summing the products of each surface area and its absorption coefficient. | A = \sum_i S_i\alpha_i |
ACX9 | Sound pressure level in decibels referencing measured pressure to the standard hearing threshold of 20 micropascals. | SPL = 20\log_{10}\frac{p}{p_{ref}} |
Compute with one of these
curl -sS -X POST https://zeqsdk.com/api/zeq/compute \
-H "Authorization: Bearer $ZEQ_KEY" \
-H "Content-Type: application/json" \
-d '{"operators":["AC1"],"inputs":{}}'
The response carries the bare physics value, its unit and uncertainty, the generated master equation, and a signed envelope you can verify on any node.
See also
- The solvers — how an operator becomes a physical answer
- Operator selection — how a query picks operators
- All categories — the full reference index