What is CTA-2118?
ANSI/CTA-2118, officially titled "Four Frequency Pure Tone Average Testing Methodology and Hearing Wellness Reporting Metric for Consumer-Facing Hearing Solutions", is a voluntary U.S. standard developed by the Consumer Technology Association (CTA) in collaboration with hearing health experts and device manufacturers. It was formally approved by the American National Standards Institute (ANSI) in 2023.
This standard provides a unified framework for:
- Measuring hearing thresholds using pure tone threshold (PTT) audiometry ,
- Standardizing test conditions and methodologies for consumer-grade hearing assessments,
- Reporting hearing ability in a consistent, easy-to-understand format for end users, relying on the Four-Frequency Pure Tone Average (PTA4).
By promoting consistent terminology and methodology, ANSI/CTA-2118 helps bring transparency, trust, and comparability to hearing health solutions across consumer electronics.
The full standard is available via the CTA Store.
Key components of the standard
- Pure Tone Thresholds Testing: Measures absolute hearing thresholds at 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz - frequencies critical for speech recognition and communication.
- Testing Methodology: Defines how and under what conditions tests should be conducted. Emphasis is placed on repeatability, validity, and standardization, especially for non-clinical, consumer-facing environments.
- Reporting Metric (PTA4): Hearing test results should be presented using the PTA4, a reliable indicator of general hearing ability. This metric provides a simple, intuitive format that supports user understanding and informed decision-making.
Mimi’s Pure Tone Threshold (PTT) test
Mimi has been a pioneer in the domain of consumer hearing testing, and has been offering a PTT test for smartphones, developed by our in-house research and product teams, for almost a decade. We have continuously refined and validated our hearing test in collaboration with academic partners following strict scientific methods.
Mimi offers a Pure Tone Threshold (PTT) Test that measures the quietest sound a person can detect. The test takes less than 2 minutes per ear, during which the user listens to various tones at different levels and frequencies and indicates when they can hear them. The test is designed for use in non-clinical settings, enabling accessibility without sacrificing accuracy.
The hearing test follows the suggested procedures and methods for consumer hearing testing, in particular in regards to user training, noise monitoring and hearing test methodology. Our test meets the ANSI/CTA2118 standard, ensuring accuracy and reliability for users. By measuring thresholds at 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz, the Mimi test covers an even broader range of frequencies than suggested by the standard.
In line with the standard, Mimi test results include the PTA4, while also reporting additional metrics and information about the users hearing ability - including hearing grade, hearing percentage and a hearing sensitivity graph* for both ears. *limited to some regions.
Making hearing health understandable with the Hearing Number
After testing is completed, PTA4 results will be displayed to users for each ear that was tested. To standardize consumer-facing terminology for hearing, results should be labeled for consumer reporting as the “Hearing Number” and/or “PTA4”. (source)
The Hearing Number is a consumer-friendly representation of hearing ability and simply tells you the softest speech sound you can hear. You have two Hearing Numbers: one for your right ear and one for your left ear. They can be as low as -10 and as high as 85 decibels (dB) or more. The higher your Hearing Numbers are, the harder it will be to hear and communicate in noisy places.
As hearing-capable consumer technology becomes more widespread, the consistent use of the Hearing Number will:
- Support comparability across products and platforms
- Enhance consumer trust through standardized, easy-to-understand metrics
- Reinforce regulatory alignment and transparency expectations in digital health and hearing care
How ANSI/CTA-2118, Mimi's PTT Test, and the Hearing Number connect
Understanding your hearing shouldn’t require a degree in audiology. That’s where standards like ANSI/CTA-2118, tools like Mimi’s Pure Tone Threshold (PTT) test, and the Hearing Number come together to simplify things.
Together, these components form a bridge between professional audiology standards and consumer-friendly experiences. Mimi’s compliance to the ANSI/CTA-2118 framework ensures that the hearing number you receive from our tests isn’t just a random score - it’s grounded in a validated testing method and reflects meaningful, real-world hearing ability.
More information
- CTA Shop: PTA4 Testing Methodology and Reporting for Consumer Hearing Solutions
- Mimi PTT hearing test: https://mimi.io/products/mimi-hearing-test
- Article: Celebrate the launch of the Hearing Number App
- More information about the Hearing Number public health campaign is available on the Bloomberg School’s Hearing Number website: www.HearingNumber.org