Acoustics

Data aquisition systems

The Acoustics Group has an extensive range of equipment for measuring sound, vibration, environmental and also physiological parameters (e.g. heart rate, skin conductance). Besides stationary measurement setups also mobile equipment is available for e.g. measurements inside aircraft.

Multichannel soundcards

Different multichannel soundcards are used for signal recordings and reproduction with mobile USB-based (RME Fireface UC) and stationary PCIe soundcards (HDSPe MADI). The combination with AD/DA-converters and microphone preamplifiers (MADI/ADAT compatible) allows for measurement setups from 2 to 64 recording and playback channels.

 

 

Binaural recording equipment

Several different artificial heads are used for binaural recordings. The heads differ in their anthropometric measures and in their pinna construction.

Some of the heads include shoulders (Head Acoustics HMSII2) or even a torso (Kemar).

The artificial heads are used for binaural recordings of sound and also binaural room impulse responses.

Multi-channel data aquisition

The SQlab II is a modular frontend for data aquisition with the software ArtemiS.

24 channels with BNC inputs for ICP microphones and accelerometers can be used simultaneously with a maximum combined bandwidth of 400 kHz. A two-channel input module for conventional (200 V) microphones is available as well. 

The system's electromagnetic emissions comply to DO-160 Cat.M allowing the use inside the cabin of airplanes in flight.

The system uses an external 12V power supply.

The DATaRec D20ix by Thales- Heim is a standalone data aquisition system recording the data on a Sony AIT tape drive.
It features 48 inputs for ICP microphones / accelerometers or other voltage sources with a maximum total dat rate of 20 Mbit/s.

The system's complies fully to MIL-STD-461C for use in civil and miltitary aircraft. The system uses an external 24V power supply

Other data aquisition systems

A number of additional, portable data aquisition systems are used in the Acoustics Group.

Bruel & Kjaer PULSE
A battery powered, 4 channel frontend for recording and processing of signals with inputs for both conventional microphones and ICP / voltage sources.

HEAD acoustics SQuadriga
Small, 4 channel flash memory based recorder for ICP microphones or accelerometers. Maximum sample rate of 48 kHz for each channel. Can also be used as a USB frontend.

HEAD acoustics MHS III
Two channel frontend with calibrated headphones for recording and playback. Specially designed for psychoacoustical test in combination with the software NoiseBook.

Marantz PMD 670 / 671
Two channel solid state recorders.

Recording noise and vibration inside an EC 135 helicopter

An example of data aquisition in an Eurocopter EC 135 helicopter is shown below.
Noise was recorded with a HEAD acoustics HMS II.2 dummy head and with several microphones.
Triaxial accelerometers were placed on the floor and seat slides to record the vibration.