Acoustic check reverberation measurement

The Nureva^® App is a companion app designed to enhance the setup and configuration of HDL310 and HDL410 systems, as well as manage a comprehensive range of audio device settings. The Nureva App is available from the Apple^® App Store (iOS, iPadOS^®) and through a web browser by using the IP address for a Nureva Pro series device.

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What is reverberation?

Room reverberation is the measure of how reflective the surfaces are within a room. The more absorbing (less reflective) the surfaces are, the better the microphones will pick up the conversations. Higher reverberation and reflections of speech will cause signal interference and more difficulty in understanding the conversation.

We recommend a reverberation time (RT60) between 0.2 and 0.6 s.

Items such as glass, concrete, brick and cinder block are highly reflective and can cause high reverberation in a room, whereas carpet and ceiling tiles are more absorptive. Adding fabric acoustic paneling on highly reflective surfaces will help with room reverberation.

Although Microphone Mist technology will work in highly reverberant rooms, adding acoustic treatments (e.g., acoustic panels, diffusers) will enhance the audio quality and assist with delivering optimal performance.

Tips for taking a reverberation measurement

• Wearing ear protection is recommended.

• The measurement is taken using the iPhone microphone.

• For optimal results, point the microphone upwards. This means holding the iPhone upside down.

• The measurement should be taken when the room is quiet (i.e. no talking).

• Position the iPhone near the intended location for the microphone and speaker bar.

• The iPhone should be about 3 ft from the wall and 5 ft above the floor.

Steps for taking a reverberation measurement

1. Open the Nureva App on an iPhone.

2. Press on Start acoustic check.

3. Select Reverberation.

4. Enter the room dimensions.

5. Inflate a balloon to about 8 inches.

6. Position the balloon in the center of the room at least 6 ft from the iPhone.

7. Press Start and point the iPhone microphone upwards.

8. Pop the balloon and wait for the measurement to complete. Remain quiet (do not talk) until the measurement is completed.

9. Press Done when you are finished taking reverberation measurements.

Recommended range and values

We recommend a reverberation time (RT60) between 0.2 and 0.6 seconds. Reverberation measurements will fall into one of three categories.

Short reverberation time (green dot)

The sound energy in this room decays quickly. Conditions are ideal for microphones to accurately target talkers anywhere in the room. Proceed with installation and default settings.

Moderate reverberation time (amber dot)

The sound energy in this room decays slowly. Echo leaks are possible but should be minimal. Remote listeners may hear changes in tonal quality. Proceed with installation and reduce the speaker bass levels if needed.

Long reverberation time (red dot)

The sound energy in this room decays particularly slowly. Echo leaks will be noticeable and remote listeners will hear hollow audio.  Contact Nureva technical support for additional advice.

Additional information

Why is it suggested to use balloons when conducting a reverberation check?

• Popping a balloon is a simple way to produce a high energy sound event containing a wide frequency rage that radiates in all directions.

What if a balloon is not available?

• Clapping your hands loudly or banging a book on the edge of a table can create similar sound events, but it is not as consistent. Multiple tests may be required.

What type of balloons can be used for the reverberation measurement?

• We recommend using a balloon made from high-grade latex.