Source: https://guthlabs.ai/docs/instruments/microphone-polar-pattern-proximity-effect-reference/implementation/

instrument implementation / implementation-contract

# Microphone Polar Pattern / Proximity Effect Reference implementation

A source-bound implementation contract for Microphone Polar Pattern / Proximity Effect Reference; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t6-063

**Effect**: Computation or source lookup only

## Input and validation requirements

A very large JSON angle such as 1e309 becomes Infinity in JavaScript, causing Math.cos(Infinity) to return NaN for cardioid and figure-8. The instrument should reject non-finite angles but may instead render undefined or corrupted plot data. The unspecified angle unit also permits materially different sensitivity values.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "pattern": "cardioid",
    "angle_deg": [
      0,
      90,
      180
    ]
  },
  "expected_outputs": {
    "sampled_points": [
      {
        "angle_deg": 0,
        "relative_sensitivity": 1
      },
      {
        "angle_deg": 90,
        "relative_sensitivity": 0.5
      },
      {
        "angle_deg": 180,
        "relative_sensitivity": 0
      }
    ],
    "key_curve_features": {
      "maximum": {
        "angle_deg": 0,
        "value": 1
      },
      "rear_null": {
        "angle_deg": 180,
        "value": 0
      },
      "range": [
        0,
        1
      ]
    }
  },
  "working": "theta=0 degrees=0 radians: cos(0)=1; sensitivity=0.5+0.5*1=1.000000. theta=90 degrees=pi/2 radians: cos(pi/2)=0; sensitivity=0.5+0.5*0=0.500000. theta=180 degrees=pi radians: cos(pi)=-1; sensitivity=0.5+0.5*(-1)=0.000000. The cardioid maximum is at 0 degrees and the rear null is at 180 degrees."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/microphone-polar-pattern-proximity-effect-reference/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/microphone-polar-pattern-proximity-effect-reference/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/microphone-polar-pattern-proximity-effect-reference/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche6/tranche6-results.json`