- What You Are Actually Studying For
- Before You Study: The CETa Prerequisite and Exam Mechanics
- Reading the Official Competency Document the Right Way
- The Eight Domains and What to Master in Each
- The Math You Should Be Able to Do Without Hesitation
- Sequencing Your Prep Around the Domains
- Test Day: Proctoring, ID and Allowed Materials
- The Free Retake and What Comes After You Pass
- Where the Credential Gets Used
- Frequently Asked Questions
- CAT is ETA International's Commercial Audio Technician credential: 100 questions, two hours, 75% to pass, $80 exam fee.
- CAT is not stand-alone; the Associate CETa certification must be earned first, and its cost is separate.
- The official competency document lists eight categories with no published weighting, so study all eight rather than gambling on one.
- One free retake is available within one year of your first examination session.
What You Are Actually Studying For
Commercial Audio Technician (CAT) is a Journeyman-level specialty certification from ETA International. It covers the design, installation and troubleshooting of speech and music sound systems in commercial and institutional environments: think conference rooms, houses of worship, school auditoriums, retail spaces and public-address installations. If you have been trying to pin down the basics first, the overview articles on what CAT is and what CAT stands for cover the definitions; this guide assumes you have decided to sit the exam and want a plan.
The format is straightforward. The exam has 100 questions, you get two hours, and you need 75% to pass. No hands-on assessment is required, so this is a knowledge test: you will not be asked to terminate a cable or tune a room on camera. That does not make it trivial. The competencies are practical, and the questions reward people who have actually thought through why a system behaves the way it does. For a candid read on difficulty, see our guide on how hard the CAT exam is.
Before You Study: The CETa Prerequisite and Exam Mechanics
The single most common planning mistake is starting CAT prep without checking the prerequisite. ETA's CAT-specific competency document states that CAT is not a stand-alone credential: the Associate Certified Electronics Technician (CETa) certification must be acquired first. If you do not already hold CETa, that is step one, and it is a separate exam with its own preparation and cost. The details are laid out in CAT requirements and eligibility.
Cost and Numbers at a Glance
| Item | CAT Detail |
|---|---|
| Governing body | ETA International |
| Classification | Journeyman |
| Exam fee | $80 USD |
| Questions | 100 |
| Time allowed | Two hours |
| Passing requirement | 75% |
| Hands-on assessment | Not required |
| Certification term | Four years |
| Retake | One free retake within one year of the first session |
| Prerequisite | CETa certification (separate cost) |
On the scoring side, 75% of 100 questions means you need 75 correct answers. There is no benefit to agonizing over scaled-score theory; what matters is that you can afford to miss at most 25 questions. Details are in our piece on the CAT passing score.
Reading the Official Competency Document the Right Way
ETA publishes a 14-page document titled Commercial Audio Technician - CAT: Categories Listing and Competencies Requirements. It is the primary scope source for the exam, and it should be the backbone of your preparation. Two cautions are worth stating plainly.
- It carries a 2013 copyright. That date is not evidence of a 2026 exam revision, and you should not assume anything about how recently the question pool changed. Treat the document as the authoritative scope statement and verify current details with ETA before you register.
- It publishes no percentage weighting. You will find eight major competency categories, but no official statement that one carries more weight than another. Do not trust any source that tells you "Domain X is 30% of the test." Equal weighting is not implied either. The safe assumption is that every category can show up and that none can be skipped.
The practical method is to turn each competency line in that document into a self-check question: "Can I explain this, calculate this, or troubleshoot this?" Anything you answer with hesitation goes on your weak list. For a domain-by-domain walkthrough, pair this guide with the complete guide to all eight CAT content areas.
The Eight Domains and What to Master in Each
The eight categories below retain the names used in ETA's competency document. The bullet points under each are the kinds of topics a commercial audio technician is expected to handle, framed as study targets rather than a claim about exact question wording.
Domain 1: Acoustics
Sound behaves differently in different rooms, and commercial installers are paid to anticipate that behavior.
- How sound propagates, reflects, absorbs and diffracts in enclosed spaces
- Reverberation and how room surfaces and volume influence intelligibility
- Why hard, parallel surfaces cause problems and how treatment changes them
- The relationship among frequency, wavelength and speed of sound
- Feedback: what causes it and how placement and gain structure control it
Domain 2: Microphones
Expect questions on selecting and placing the right transducer for the job.
- Dynamic versus condenser operation and when each is appropriate
- Polar patterns (omnidirectional, cardioid and similar) and their rejection characteristics
- Phantom power: what it is, what needs it and what does not
- Balanced versus unbalanced connections and why balanced lines reject noise
- Placement principles for speech versus music pickup
Domain 3: Speakers
Loudspeaker knowledge links the acoustic and the electrical sides of the exam.
- Driver types, crossovers and how frequency ranges are divided
- Impedance, power handling and sensitivity ratings
- Coverage patterns and how they influence speaker placement in a room
- Amplifier-to-speaker matching, including what happens when impedance is mismatched
- Ceiling, wall-mounted and distributed loudspeaker applications
Domain 4: Sound & Measurements
This domain is where numeracy matters most.
- Decibels: the logic of the scale, and how gain and loss are expressed
- Sound pressure level and how distance affects it
- Frequency, wavelength and period relationships
- Using meters and test equipment to verify levels and system performance
- Signal-to-noise ideas and headroom as practical measurement concepts
Domain 5: Wiring
The best-designed system fails if the cabling is wrong.
- Cable types and appropriate use for microphone, line and speaker runs
- Wire gauge, run length and the resulting loss
- Connector types and correct termination practices
- Grounding, shielding and strategies for avoiding hum and interference
- Series versus parallel speaker wiring and the impedance consequences
Domain 6: 70-Volt Systems
Constant-voltage distribution is a signature topic of commercial sound and deserves dedicated study time.
- Why distributed systems use transformers and elevated line voltage for long runs
- Tap settings on line transformers and how they set each speaker's power draw
- Totaling speaker power taps and sizing the amplifier with sensible headroom
- Calculating load, and recognizing an overloaded or mis-tapped line
- When constant-voltage is the right design choice versus low-impedance wiring
Domain 7: Troubleshooting
Troubleshooting questions test reasoning more than recall.
- Working from symptom to cause: no signal, distortion, hum, noise, intermittent dropouts
- Signal-flow tracing, from source through processing and amplification to the loudspeaker
- Isolating a fault by dividing the system and testing section by section
- Recognizing the usual suspects: bad connections, ground loops, gain-structure errors, mismatched loads
- Selecting appropriate test equipment for a given symptom
Domain 8: Safety, Codes and Standards
Do not treat this as the easy filler section; it is where careless candidates drop avoidable points.
- Electrical safety fundamentals when working around powered equipment
- Safe practices for mounting, rigging and working at height
- Code and standards awareness relevant to installed audio wiring
- Hearing safety and responsible sound-level practice
- Professional practice around documentation and customer-facing responsibilities
The Math You Should Be Able to Do Without Hesitation
Commercial audio is applied electronics, and the exam expects you to be comfortable with basic calculations. You do not need advanced mathematics, and ETA's general examination rules permit a nonprogrammable scientific calculator, but you should know which relationship to reach for before you touch the keypad. The formulas below are standard, well-established relationships, not anything specific to one exam bank.
- Ohm's law and power: the relationships among voltage, current, resistance and power underpin amplifier loading and line-loss reasoning.
- Series and parallel impedance: practice combining loads until you can predict the result of wiring several speakers together.
- Decibel relationships: know the logic of gain and loss in decibels and how voltage and power ratios differ.
- Wavelength: speed divided by frequency, and what that implies for room dimensions and speaker spacing.
- 70-volt power budgeting: add up the tap wattages, then confirm the amplifier is rated comfortably above the total.
Sequencing Your Prep Around the Domains
Since the competency document gives no weighting, a sensible plan spreads time across all eight categories and front-loads the ones that other topics depend on. Acoustics and measurements come first because decibels and sound behavior show up inside nearly every other domain. Speakers and wiring come before 70-volt systems because constant-voltage design builds directly on impedance and load concepts. Troubleshooting comes late because it draws on everything else. Safety, codes and standards should not be saved for the last night; read it early and revisit it.
Acoustics and Sound & Measurements
- Build fluency with decibels, frequency and wavelength
- Read the matching competency lines and mark weak spots
Microphones and Speakers
- Memorize pickup patterns, power requirements and driver behavior
- Practice impedance and power-handling questions
Wiring and 70-Volt Systems
- Work series/parallel and gauge-versus-length problems
- Do repeated tap-total and amplifier-sizing exercises
Troubleshooting, Safety, Codes and Standards, then Full Review
- Trace signal flow on sample systems and reason from symptom to cause
- Sit full timed practice sets and revisit every missed question
If your schedule is tighter or looser than four weeks, keep the order and stretch or compress the blocks. The one-page review in our CAT cheat sheet is a useful companion in the final days, and the CAT practice tests let you rehearse the 100-question, two-hour pacing before the real thing.
Test Day: Proctoring, ID and Allowed Materials
Exams are proctored through an ETA Certification Administrator, using either Trapeza online testing or paper and pencil. The standard Trapeza route requires an onsite administrator. ETA also offers a distinct remote-proctoring route through ExamRoom.AI. Which route is available to you depends on your administrator and circumstances, so confirm the details before you commit to a date. Scheduling considerations are covered further in our guide to CAT exam dates and scheduling.
- Photo identification is required. Bring valid ID and make sure the name matches your registration.
- A nonprogrammable scientific calculator is permitted under ETA's general examination rules. Check that yours qualifies; a programmable model is a risk not worth taking.
- Scratch paper is allowed, and you will surrender the used sheets when you finish.
- Pace yourself. Two hours for 100 questions averages out to roughly a minute and a half per question, which leaves a little slack for the calculation-heavy ones. Answer what you know first, flag the rest and come back.
The Free Retake and What Comes After You Pass
ETA allows one free retake within one year of your first examination session. That safety net is real, but it is better treated as insurance than as a plan. If you do need it, use your score feedback to find which domains cost you points, rebuild those topics and avoid simply re-reading everything. For a data-minded look at outcomes, see our article on the CAT pass rate, which explains what can and cannot be said about it.
Passing earns you a four-year certification term. CAT follows ETA's general Maintenance track, not Maintenance with Hands-On. To keep the credential current you submit the maintenance form and satisfy one of two paths: either 10 continuing-education hours per year (40 over the four years), or qualifying supervisor-completed employer verification. Either way, the fee is $25 per year, totaling $100 across the four-year cycle. Factor these ongoing costs into your thinking when you weigh the credential; our ROI analysis of CAT certification and salary guide take that long view.
Where the Credential Gets Used
The skills CAT validates map onto work in commercial and institutional sound: integration and installation companies, facilities and maintenance teams that look after building audio systems, houses of worship, schools and universities, and venues that depend on distributed or paging systems. Because the credential is classified as Journeyman and sits on top of CETa, it signals that a technician has both baseline electronics grounding and applied audio competence. Browse CAT jobs for a closer look at how employers frame these roles, and our CAT training overview if you are deciding how to build skills before you test.
Key Takeaway
Because the competency document publishes no domain weighting, the winning strategy is breadth with depth where it counts: be solid on all eight categories, and make 70-volt systems, wiring and the decibel math truly automatic.
Frequently Asked Questions
Yes. ETA's CAT competency document states that CAT is not a stand-alone credential and that Associate Certified Electronics Technician (CETa) certification must be acquired first. The CETa has its own exam and cost, separate from the $80 CAT fee.
The exam has 100 questions, you have two hours, and you need 75% to pass. There is no hands-on assessment component.
ETA does not publish percentage weighting for the eight categories, so no domain can be called the largest, and equal weighting should not be assumed either. Prepare across all eight: Acoustics, Microphones, Speakers, Sound & Measurements, Wiring, 70-Volt Systems, Troubleshooting, and Safety, Codes and Standards.
One free retake is available within one year of your first examination session. Use the time between attempts to target the domains where you lost the most points rather than restarting your study from scratch.
The term is four years. You submit the maintenance form and either complete 10 continuing-education hours per year (40 total) or provide qualifying supervisor-completed employer verification, and you pay $25 per year, which comes to $100 over the cycle.
Start by confirming your CETa status, download the official competency document, and then test yourself against it using the CAT practice tests. With a domain-by-domain plan and a clear picture of the exam mechanics, your first attempt can also be your last.