USB Audio Option

The USB Audio Option allows the instrument to be recognized by the host computer as a USB Microphone.

The USB Audio Option is only applicable to the NSRT_mk3, NSRTW_mk3, NSRT_mk3_Dev and NSRT_mk4_Dev.

It is included in the NSRT_mk4 and NSRTW_mk4.

 

Applications

That option is useful to users who want to:

  • Use the Noise Sentry series of Sound Level Meters with off-the-shelf audio analysis and processing software that can work from a USB Microphone.
  • Develop their own acoustics analysis or monitoring application on any platform that recognizes a standard USB microphone.

The USB-Microphone interface streams a mono audio signal, like any standard USB microphone, except the pressure signal is calibrated in Pa and weighted by the selected weighting function (A, C or Z).

 

Compatibility

  • Windows (Tested on Windows 7 and 10)
  • Mac-OS (Tested on OS-X El Capitan)
  • Linux (Tested on Rasberry Pi 3b on Raspbian Buster)

OS interference

Some hosts (for instance Windows) will attempt to take control of the USB microphone as soon as it is connected to the host. In some situations that can lead to issues, including a termination of an ongoing recording of levels. This occurs when the host attempts to change the sampling frequency of the instrument to one that is different than the one currently in effect. Because it is mandated by the USB audio specification, the instrument has no choice but to comply with the USB request. If the instrument was already recording at a different sampling frequency, this may lead to a transient due to the switch, or a termination of the ongoing recording, depending on the firmware of the instrument. In order to avoid that situation one can deselect the instrument as the default USB recording source on the host, or set it to the same sampling frequency as the sampling frequency used to record the levels.

If you purchased the Audio option separately from the instrument, refer to the following web page for installation instructions.

Don’t hesitate to contact [email protected] if you have any question.

Product Description

The USB Audio Option allows the instrument to be recognized by the host computer as a USB Microphone.

The USB Audio Option is only applicable to the NSRT_mk3, NSRTW_mk3, NSRT_mk3_Dev and NSRT_mk4_Dev.

It is included in the NSRT_mk4 and NSRTW_mk4.

 

Applications

That option is useful to users who want to:

  • Use the Noise Sentry series of Sound Level Meters with off-the-shelf audio analysis and processing software that can work from a USB Microphone.
  • Develop their own acoustics analysis or monitoring application on any platform that recognizes a standard USB microphone.

The USB-Microphone interface streams a mono audio signal, like any standard USB microphone, except the pressure signal is calibrated in Pa and weighted by the selected weighting function (A, C or Z).

 

Compatibility

  • Windows (Tested on Windows 7 and 10)
  • Mac-OS (Tested on OS-X El Capitan)
  • Linux (Tested on Rasberry Pi 3b on Raspbian Buster)

OS interference

Some hosts (for instance Windows) will attempt to take control of the USB microphone as soon as it is connected to the host. In some situations that can lead to issues, including a termination of an ongoing recording of levels. This occurs when the host attempts to change the sampling frequency of the instrument to one that is different than the one currently in effect. Because it is mandated by the USB audio specification, the instrument has no choice but to comply with the USB request. If the instrument was already recording at a different sampling frequency, this may lead to a transient due to the switch, or a termination of the ongoing recording, depending on the firmware of the instrument. In order to avoid that situation one can deselect the instrument as the default USB recording source on the host, or set it to the same sampling frequency as the sampling frequency used to record the levels.

If you purchased the Audio option separately from the instrument, refer to the following web page for installation instructions.

Don’t hesitate to contact [email protected] if you have any question.

Installation

There are two cases:

  • If the option is purchased together with the instrument, the instrument will be delivered already configured with the option activated.
  • If the option is purchased to install on an existing instrument, follow the procedure below to activate it:
    1. Email [email protected] with the serial number of the target instrument and the invoice number for the purchase of the USB Audio Option. That serial number must be copied from the SN field in Instrument Manager and pasted in the email. This way there is no risk of typo when creating the activation key.
    2. We will email back with an activation key (a small file), and a link to the installer for activation application. The activation application only works on Windows.
    3. Download and install the activation application. Unzip the activation key, if it has been compressed for the purpose of emailing it.
    4. Connect the instrument to the PC. Make sure that ONLY the target instrument, and no other NSRT_mk3 or NSRTW_mk3 is connected to the PC. Make sure the PC has recognized the instrument and its operation LED is blinking.
    5. Run the activation application. When asked, point to the activation key that was emailed for that instrument. Make sure the activation application recognizes the type of instrument and properly indicates that it will be converted to the same instrument with the Audio option (see Figure 1).
    6. Click the Activate button (see Figure 1)
    7. After working for a few seconds, the right-side panel will indicate “Waiting for Driver Reload” (see Figure 2). That step can last for a few minutes. The PC is looking for the appropriate driver for the instrument with the Audio option. Do not interrupt that step or disconnect the instrument.
    8. After reloading the driver, the new firmware will be installed. That step takes a few seconds.
    9. In the end, a completion message will appear. At that time make sure the PC has loaded the generic audio driver for the Audio interface. The NSRTW_mk3_Audio should appear in the recording devices. It is possible that the PC will still be trying to find and load a generic driver for the Audio interface. If so, wait until the PC has finished loading the Audio driver and recognized the instrument as a recording device. Do not disconnect the instrument until the PC has loaded the Audio driver. That step can take a few minutes.

 

Figure 1

Figure 2

 

 

Specifications

Formats

PCM 16-bit integer, IEEE 32-bit float
Sampling rates

32 kHz, 48 kHz
Volume and Mute

Volume and mute can be adjusted through the audio interface. The volume has no effect when the IEEE float format is chosen. In that case the sample values represent the sound pressure, scaled in Pa, irrespective of the value of the Volume control.

60.00 $

SKU AUDIO Category Tag

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