Every hearing conservation vendor will tell you their model is better. Mobile van providers emphasize no equipment investment and turnkey scheduling. In-house digital programs emphasize flexibility and data continuity. Neither pitch gives you the analytical framework to make the decision for your specific operation. This guide does.
Soundtrace provides in-house digital audiometric testing that operates without a sound booth — using validated ambient noise monitoring and RadioEar DD65V2 circumaural headsets to deliver ANSI S3.1-compliant testing at your facility, on your schedule, integrated with real-time noise monitoring and professional supervisor oversight.
The core difference between these models is scheduling control. Mobile van programs operate on the vendor’s calendar; in-house programs operate on the employer’s. Every other practical difference — baseline timing, STS retests, data access — flows from that single distinction.
How Each Model Works
🚌 Mobile Van Audiometry
A vendor operates a vehicle-mounted sound booth that visits the employer’s facility once or twice per year.
Testing is conducted during the visit; audiogram results are reviewed by a remote audiologist after the visit.
Records are held in the vendor’s proprietary system.
Testing schedule is set by the vendor’s route calendar, not the employer’s needs.
🏢 In-House Digital (Boothless)
The employer tests at their own facility year-round using validated audiometric equipment without a traditional sound booth.
Professional supervisor review is conducted remotely, typically within days.
All records are in the employer’s digital system with full access and portability.
Testing schedule is set by clinical need: baselines, retests, and risk-based surveillance on demand.
▶ Bottom line: The core difference is scheduling control. Mobile van programs operate on the vendor’s calendar; in-house programs operate on the employer’s. Everything else flows from that distinction.
Scheduling and Compliance Window Risk
OSHA’s “annual” means within 12 months of the previous test. A mobile van that visits once per year creates a compressed testing window. Key compliance risks that only in-house programs fully address:
- New hire baselines within 6 months: If the van already visited this year, new employees must either wait (compliance gap) or get tested at an external clinic at added cost.
- STS retests within 30 days: If an STS is identified after the van visit, the 30-day retest window requires either an expensive emergency van return or sending the worker offsite.
- Multi-shift coverage: Annual van visits rarely accommodate all shifts. Night shift workers frequently miss their annual audiogram entirely.
- Semi-annual testing for high-risk employees: Workers with exposure above 100 dBA or confirmed STS histories who need more than annual testing cannot be accommodated by annual van schedules.
▶ Bottom line: Mobile van programs pass compliance on paper when everything goes perfectly. When a shift is missed, an employee is absent, or an STS retest is needed, the annual-visit model creates compliance gaps that in-house programs handle routinely.
Ambient Noise Standards: The Booth and Boothless Question
Mobile vans use a physical sound booth built into the vehicle. Modern in-house digital programs use validated high-attenuation circumaural headsets with real-time ambient noise monitoring. The critical compliance question is not which approach is used — it’s whether ambient conditions are documented per test.
Soundtrace uses the RadioEar DD65V2 with event-level ambient validation — confirming noise adequacy at the time of each threshold response rather than assuming a static environment. Both approaches can produce valid audiograms; what distinguishes them is the strength of documentation.
▶ Bottom line: Both models can produce valid audiograms. What matters is that the ambient noise standard is documented per test and consistently applied. A boothless program with event-level ambient logging produces stronger documentation than a van program with only pre-session checks.
Cost Comparison: The Full Picture
| Cost Element | Mobile Van | In-House Digital |
|---|---|---|
| Per-test direct cost | Higher at small volume; competitive at large | Generally lower per-test at most volumes |
| Missed employee make-up visits | Additional cost per visit or clinic referral | No additional cost; retest on site within days |
| STS retest logistics | Additional van visit or outside clinic cost | Included; conducted on-site within 30 days |
| New hire baseline scheduling | Often requires make-up visit or clinic referral | Conducted on enrollment; no additional cost |
| Administrative burden | Annual rounding up of employees; high disruption | Distributed throughout year; integrates with onboarding |
| Data portability on vendor change | May be difficult; records in vendor system | Employer controls data; portable on demand |
▶ Bottom line: Per-test cost comparisons undercount the true cost of mobile van programs. Total program cost — including make-up visits, STS retests, new hire baselines, and administrative burden — is the correct comparison metric.
Data Access and Continuity
Mobile van programs store audiometric records in the vendor’s proprietary system. When an employer switches vendors, historical audiograms may be difficult to transfer, creating baseline continuity problems. In-house programs where the employer controls their data eliminate this risk entirely.
Ask any audiometric vendor: if we end our relationship tomorrow, can we export our complete audiometric records in a standard format that can be imported by another system? The answer tells you everything about actual data portability. For the 30-year OSHA record retention requirement, vendor-locked records are a long-term liability.
STS Follow-Up: Where the Models Diverge Most
In a mobile van program, the STS is typically identified after the van visit — often weeks after the test. This compresses the 21-day notification window and the 30-day retest window simultaneously. In an in-house digital program, the professional supervisor can review audiograms within days of the test. STS cases are flagged promptly, and the 30-day retest is easily scheduled at the employer’s facility with no additional cost or logistics.
An STS identified 3 weeks after a van visit leaves only 9 days to schedule and complete a retest. If that window is missed, the employer loses the ability to use retest results and may be required to proceed with follow-up actions based on results that could have been TTS-related. This is not a hypothetical risk — it is a structural weakness of the annual-visit model.
Workforce Characteristics That Favor Each Model
Mobile van programs suit very specific situations: single-site operations with 25 or fewer enrolled employees, single-shift schedules with high predictability, low turnover (few new hire baselines needed between visits), and low STS rates (few retests needed). In-house digital programs suit the majority of industrial employers: multi-shift operations, facilities with meaningful turnover, operations with elevated noise exposures and corresponding STS rates, multi-site employers, and any employer where documentation quality is a priority.
Decision Framework
Ask these questions to identify the right model for your operation. How many employees are enrolled and how much does that change due to turnover? How many shifts do enrolled employees work? What is the current STS rate and how many retests were needed recently? Were documentation gaps identified in your last inspection? How important is continuity of audiometric records if you change vendors? The answers point clearly toward in-house for most industrial operations with more than a handful of enrolled employees or any meaningful workforce complexity.
Frequently asked questions
In-House Digital Audiometry: On Your Schedule, At Your Facility
Soundtrace delivers OSHA-compliant audiometric testing without a sound booth, on your schedule, with continuous access to your audiometric data and same-day STS follow-up capability.
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