Psychoacoustics & Accessibility 12 & 13

Human Hearing Atlas & The Accessibility Mix

Sound exists physically, but hearing is biological and listening is cognitive. Sourced from CDC NHANES audiometry survey cycles, explore measured population thresholds from 250 Hz to 8 kHz, audition simulated age-related high-frequency decline, and learn how multisensory UI design protects users with hearing variations.

Psychoacoustics & HealthCDC NHANES Pure-Tone Audiometry Surveys (1999–2020)

Human Hearing Atlas & Accessibility Mix

SCIENTIFIC NOTIFICATION & PSYCHOACOUSTIC DISCLAIMER

SCIENTIFIC NOTICE: All hearing threshold simulations and audiometric data displayed in Sonologium are derived from CDC NHANES population-weighted survey cycles for educational and psychoacoustic exploratory purposes. They do not constitute clinical diagnosis or medical evaluation. Individuals experiencing hearing difficulties should consult a licensed audiologist.

Cohort: Ages 20–29 // Classification: Normal Hearing Sensitivity

Pure-Tone Air Conduction Audiogram

0 dB HL (Normal Hearing Threshold)80 dB HL (Severe Sensorineural Loss)

250 Hz 5 dB HL

500 Hz 5 dB HL

1000 Hz 4 dB HL

2000 Hz 4 dB HL

3000 Hz 6 dB HL

4000 Hz (Vulnerable 4 kHz Notch)7 dB HL

6000 Hz 8 dB HL

8000 Hz 8 dB HL

Consonant Intelligibility in Background Noise:98.5%

Full perception of upper musical harmonics, spatial localization cues from pinna reflections (above 6 kHz), and crisp consonant intelligibility (s, th, f).

The Accessibility Mix (Sonologium × Chromologium)

Prohibit Single-Frequency 4 kHz UI Alerts

Use multi-octave harmonic chimes containing robust energy in the fundamental band between 400 Hz and 1,200 Hz, with high-frequency components serving strictly as decorative sheen.

Chromologium enforces WCAG 2.2 color contrast ratios; Sonologium enforces acoustic spectral redundancy so no critical signal relies on a single vulnerable auditory frequency.

Mandatory Multisensory Visual/Haptic Redundancy

Every auditory notification must trigger simultaneous synchronized visual feedback (e.g. high-contrast banner toast or border pulse) and haptic vibration where supported.

Pairs directly with Chromologium's warning tokens: an alert sound triggers both an audio harmonic pulse and an OKLCH amber/rose visual beacon.

Maintain +15 dB Signal-to-Noise Ratio for Spoken Media

Ducking: automatically attenuate background audio beds by at least 18 dB during vocal narration, and provide a dedicated 'Dialogue Boost' high-pass speech presence filter.

Analogous to font weight and legibility against textured backgrounds: clear separation between foreground signal and background substrate.