Audiology Booth Product

Overview

An audiology booth (also called a sound booth or isolation booth) is a small, fully enclosed chamber designed to attenuate external noise and achieve a sufficiently quiet interior environment for hearing assessment. The booth allows an audiologist or hearing healthcare professional to administer standardized hearing tests (pure-tone audiometry, speech discrimination testing, tinnitus evaluation) uncontaminated by ambient room noise. A typical audiology booth measures ~2 m × 2 m × 2.1 m (interior), achieves 40–50 dB sound isolation depending on design, and maintains interior background noise below 25 dB(A)—the threshold at which the softest audible tones can be accurately measured without contamination.

The booth structure consists of a Frame & Support Structure (welded steel or modular aluminum), with Acoustic Wall Panels (acoustic sandwich construction), a Sealed Entry Door (heavy, gasketed entry), and a Observation Window (double-pane laminated glass for observation). A Ventilation with Sound Silencing supplies fresh air and exhausts stale air through silencers to prevent external noise ingress. Internal Electrical Jack Panel (Audiometer Interface) provides power and signal connectors for audiometer and patient response equipment.

Wall construction and acoustic design

The Acoustic Wall Panels are the acoustic core of the booth. Each panel is a three-layer composite: an outer facing (12 mm MDF or plywood), 50 mm of rockwool or fiberglass insulation, and an inner backing sheet. The air gap between the panel exterior and the booth frame creates a secondary mass-spring system, improving low-frequency absorption. Typical isolation at 1 kHz is 45 dB; at lower frequencies (250 Hz), isolation may be 35–40 dB, which is adequate for most hearing testing.

The Acoustic Rockwool Fill material (density 96 kg/m³) absorbs sound energy across the 125 Hz to 4 kHz range, critical for reducing reverberation within the booth. Panels are mounted via Panel Mounting Clips that allow mounting without penetrating the acoustic layer. Seams are sealed with Corner Seal Gasket gasket strips, preventing air leaks that would degrade isolation.

An Internal Baffle Panel panel (additional absorbing divider) is sometimes mounted diagonally or vertically inside the booth to further reduce standing wave resonances and flutter echo, improving the acoustic environment.

Door system

The Sealed Entry Door is critical to maintaining isolation. The Door Panel (Solid Core) is a heavy, solid-core sandwich: 50 mm total thickness with lead sheet or rockwool core (~35 kg mass). A Door Frame Surround (hardwood or aluminum jamb) provides the opening structure. The Perimeter Gasket Set (foam or rubber strips on all four sides) compresses when the door closes, creating an air-tight seal that blocks sound transmission through the frame joint.

The audiology-booth-door-hinge is a heavy-duty stainless steel barrel hinge with teflon linings; two hinges per door handle the 35 kg weight. A Handle & Latch Assembly uses a lever handle and push-to-latch mechanism for one-hand operation. A Door Closer / Damper (hydraulic or spring-loaded damper) ensures the door closes fully and slowly, preventing slamming while maintaining a good seal.

Observation window

The Observation Window allows the audiologist to observe the patient's behavior during testing. The Laminated Acoustic Glass Pane is 6 mm toughened glass laminated with a 0.76 mm PVB (polyvinyl butyral) interlayer, providing 30–35 dB sound isolation in itself. Two panes are separated by a Window Air Gap Spacer (20 mm desiccant-filled spacer), decoupling the acoustic mass of the two panes and improving low-frequency isolation.

The Window Frame Assembly (aluminum or vinyl with thermal break) is mounted in the booth wall with Window Gasket / Bead (EPDM seal) around the perimeter, preventing air leakage.

Ventilation

The Ventilation with Sound Silencing must supply fresh air (to maintain a comfortable environment for extended testing) without introducing external noise. The Supply Air Duct draws outside air and routes it through a Supply Air Silencer (box-type silencer with 50 mm rockwool lining, ~25 dB reduction). The duct penetrates the booth wall with acoustic sealant, and air is distributed inside through a One-Way Vent Valve (damper or grille).

Similarly, the Exhaust Air Duct and Exhaust Air Silencer remove interior air, maintaining slight positive or neutral pressure to prevent pressure-driven ventilation holes from impairing the seal.

Total ventilation is typically 50–100 CFM, sufficient for a 30–60 minute testing session without accumulating carbon dioxide, but low enough that air noise is not perceptible.

Electrical and signal interface

The Electrical Jack Panel (Audiometer Interface) on the booth wall provides two or four grounded duplex outlets (15 A minimum per circuit) for powering the audiometer, patient response button box, and any ancillary equipment. The Power Inlet (230 V Single Phase) is a standard hospital-grade IEC connector mounted externally, with internal wiring routed to interior outlets via conduit.

Signal connectors (audio in/out) are critical. The RCA Jack (Signal) (stereo pair RCA connectors) and XLR Connector (balanced 3-pin XLR) allow connection of the audiometer output to a Speaker Jack (High-Power) (speaker output jack for calibrated loudspeakers or to the audiometer's headphone circuit for bone-conduction testing). A Microphone Jack allows microphone input (e.g., for patient response or background conversation logging).

All audio cabling inside the booth is kept short and routed in a Signal Cable Shield Box—an aluminum enclosure under the jack panel containing ferrite cores and signal isolation—to minimize hum and electrical noise that might contaminate sensitive audio measurements.

Interior finish and furnishings

The Interior Fixtures & Furnishings include a light-duty patient chair (low-back, stable base, allowing movement), a Interior Mirror for self-observation during speech testing, and dimmable Interior Lighting (LED panel, ~500 lux at center). The Interior Finish Paint is a low-VOC, acoustically transparent finish (not sound-absorbing, to avoid over-damping).

Clinical workflow

The patient enters the booth, the door is sealed behind them, and they are instructed to press a button or raise a hand each time they hear a test tone. The audiologist sits at a control desk (outside the booth or visible through the window) and operates the audiometer, which generates pure tones at decreasing volumes. The booth's quiet background (typically <25 dB(A)) allows the patient to hear the faintest tones—often down to 0 dB HL (hearing level), the threshold of normal hearing. Without the booth, traffic or HVAC noise would mask soft tones, artificially elevating the measured hearing threshold and potentially delaying diagnosis of hearing loss.

Modern booths are lightweight, modular, and portable—allowing temporary setup in clinics or mobile hearing screening programs. More permanent installations are fixed to the building structure and are often integrated with clinical workstations.