State of knowledge

September 2022


There are disturbances in the audio transmission. The speech sounds choppy.


Check behavior in the browser

 Launch the browser in the Incognito/InPrivate window (Ctrl+Shift+N) or in the private window (Ctrl+Shift+P)

Check the behavior of your audio devices using the following web page in a WebRTC-enabled browser at

Example screenshot: Check audio devices: WebRTC samples – Select sources & outputs

Install additional Windows software to analyze behavior in the Windows environment between audio devices and the application

By installing additional software, the audio streams (recording/playback) are recorded for review before being processed by ProCall Enterprise client for Windows.

Preparation (installation)

To determine the source of the choppy audio, Voicemeeter Banana ( is installed on the Microsoft Windows server.

Voicemeeter Banana is available under a "Donationware Model". Please refer to the corresponding terms of use of the provider.

After installing Voicemeeter Banana, a reboot of the operating system is required.

It should be noted that the audio devices can also be used by users:

Configuration for Remote Desktop Services (RDS)

To do this, it is important to start the Remote Desktop connection so that playback takes place on the "remote computer" and the headset is included as a RemoteFX (Plantronics BT600 in the example):

Play on the remote computer

Without selecting "Play on the remote computer", the required Voicemeeter VAIO/AUX audio devices are not available for selection.

When RemoteFX is activated, the device is no longer available on the local workstation PC and is used exclusively for the Remote Desktop connection.

Setting Voicemeeter Banana and ProCall Client for Windows

Schematic diagram of the interconnection

Example screenshot: ProCall audio/video wizard settings with VoiceMeeter devices

Settings in the Voicemeeter for recording

The recording mixes the microphone (HARDWARE INPUT 1 => B1 => Voicemeeter VAIO OUTPUT) and the playback (Voicemeeter AUX INPUT => A1 => HARDWARE OUT) of the ProCall client (usually the voice of the other party). The recording can be changed by selecting A1 and B1, i.e. by deselecting B1 to the right of the cassette, only A1 would be recorded, i.e. only the microphone.

Selection of different driver technologies

The abbreviations WDM, MME, KS, or ASIO can be used to select different driver technologies and thus check whether there is a change in the real-time processing (recording/playback) depending on the driver technology.

The other party must agree to the recording, i.e. agree before it is recorded. Recording only takes place if the A1 channel is activated on the cassette (green), as shown in the following image.

Example screenshot: Voicemeeter Banana hardware input 1: WDM headset microphone

Location of the recording (cassette)

Pressing the record button (yellow arrow) creates a new file each time.

The storage location can be changed via Settings (Menu/Tape Recorder Options).
The settings can also be opened with the right mouse button on the cassette:

Example screenshot: Voicemeeter Banana recorder options