Audio Exposure
Audio Exposure: The sound pressure that is created by the speakers of a headset.
Introduction
Audio exposure is the sound pressure level created by the speakers of the headset. It describes the noise levels an agent is actually exposed to when using a headset.
There are two different types of audio exposure:
- Noise peaks: You are in a webconference with your prankster friend. Then he suddenly blows an air horn into the microphone of his headset to surprise you.
- Continuous noise levels: Such as having a call in a construction zone.
Keeping audio exposure within reasonable boundaries is important for an agent’s wellbeing.
Legal regulations
Various organizations have defined their own guidelines for audio exposure:
- NIOSH (National Institute for Occupational Safety & Health)
- EU-OSHA (European Agency for Safety and Health at Work)
- MSHA (Mine Safety and Health Administration)
The guidelines usually limit both noise levels peaks and time periods of continuous noise exposure. The combination of the noise level and the time of exposition results in the maximum permittable noise dose.
NIOSH, for example, defines maximum noise doses like this:
| Exposure time | Maximum Noise Level |
|---|---|
| 8 hours | 85 dB(A) |
| 4 hours | 88 dB(A) |
| 2 hours | 91 dB(A) |
| 1 hour | 94 dB(A) |
| 30 minutes | 97 dB(A) |
| 15 minutes | 100 dB(A) |
Peak Value Protection
All approved headsets on the market must filter noise peaks. This means, that the headset alters the raw audio signal, if it exceed a certain limit. This ensures, that the user’s hearing is always protected from acoustic shock.
Jabra headsets comply with stricter standards than legally required. The protection level depends on the headset model.
| Peak Value | Description | |
|---|---|---|
| Peak value (international standard) | 140 dB(C) | Headsets of all manufacturers must comply at least to this standard. |
| Jabra Headset Maximum | 122 dB(SPL) | Maximum value for all Jabra headsets ever built. |
| Jabra PeakStop (First generation) | 118 dB(A) | Maximum value for some older Jabra headsets. |
| Jabra PeakStop (Second generation) | 105 dB(A) | Maximum value for the complete range of current Jabra headsets. |
Raw Audio Signal
The raw audio signal has the full dynamic range. It is undistorted.
This is the unaltered unprocessed audio signal. It includes high noise levels reaching 120 dB(A). High noise levels pose a risk to the agent's health.
PeakStop
PeakStop in current Jabra headsets cuts off audio signals that exceed 105 dB(A).
Jabra PeakStop feature protects users of Jabra headsets from sudden noise peaks. Any noise level above the threshold is filtered out instantly. The user is not able to hear the filtered parts of the audio signal. The audio signal is thus incomplete and distorted.
The threshold of PeakStop is fixed and cannot be disabled. But the user can configure the headset for even tighter peak limit values by using IntelliTone.
IntelliTone
IntelliTone compresses the full dynamic range of the raw audio signal into a predefined range.
The characteristic of Jabra IntelliTone is different from PeakStop. IntelliTone compresses the full dynamic range of an original audio signal to fit into a predefined range with a maximum peak value.
Dynamic range compression will change the characteristics of an audio signal. It is a matter of personal preference if a user prefers IntelliTone over the uncompressed audio signal with full dynamic range. You can configure a headset's IntelliTone settings with the desktop software Jabra Direct.
Jabra Direct (version 6.4) offers these settings for IntelliTone:
- 85 dB
- 82 dB
- 79 dB
- G.616
Datapoint Subscription
You need to subscribe this datapoint:
- Audio Exposure
Optionally, you can also subscribe these datapoints:
- Background Noise
- Volume Down Tap
- Volume Up Tap
If a user is exposed to excessive background noise, he might increase the volume of the headset. The increased volume will lead to a higher level of audio exposure.
The G.616 guideline states: “Most people require average speech levels to be about 10 dB to 15 dB above background noise for good intelligibility.” Background Noise, Audio Exposure and changes in volume level are insofar correlated.
Threshold Value
Threshold values can be freely defined according to the requirements for a specific use case.
If you follow NIOSH, threshold values can be for example:
-
Audio Exposure: 85 dB(A)
- Background Noise: 55 dB(A)
Values that exceed defined thresholds indicate that a user might be exposed to excessive noise.
Data Analysis
The data analysis primarily focuses on data values that exceed defined threshold values for Audio Exposure and optionally Background Noise. Maximum values for audio signals should not exceed the defines thresholds.
The frequency of volume control operations can give further insights. Constant changes of the volume can be an indicator that an agent is disturbed by his environment.
Example
- The agent is exposed to excessive Background Noise
- He turns up the volume to ensure the comprehensibility of the conversation
As a result, the agent is then exposed to higher Audio Exposure.