Hardware¶
The acoustic startle response setup can only record data, if the required hardware is available.
Soundcard¶
The soundcard should have at least two output channels. If two different loudspeakers for pre-stimulus and startle-stimulus should be used, the soundcard needs at least three channels:
trigger channel
pre stimulus
startle stimulus
In our setup, we use a Asus Xonar Essence STX II 7.1 soundcard (SNR: 124 dB, channels: 8, sampling rate: <192 kHz ).
Amplifier¶
Broadband low noise amplifier
Amp74, Thomas Wulf, Frankfurt
Amp75, Thomas Wulf, Frankfurt
Loudspeaker¶
The setup can either be realized with one loudspeaker or two loudspeakers. Separating the pre-stimulus from the startle-stimulus loudspeaker has the advantage, that the speaker for the pre-stimulus is not damaged by the repeated application of loud startle-pulses.
The pre-stimulus speaker should be able to reproduce the signal faithfully, while the startle-stimulus speaker only needs to be able to present a loud burst.
In our setup, we use:
Two-way loudspeaker Canton Plus XS.2 for the pre-stimulus
Neo-25s (Sinuslive) for the startle-stimulus
NiDAQ-Card¶
The data acquisition card needs at least six channels and a recording rate of 10 kHz.
In our setup, we use a PCIe-6320 data acquisition card connected to a Breakoutbox BNC-2110.
Sensor platform¶
The sensor platform has to hold the animal at a fixed distance to the speakers. In addition, the animal has to be flexibly mounted to allow for measurable vibrations when the animal twitches in response to a startle stimulus.
In our setup, we use a platform consisting of two plates. The upper plate has a mount for the animal restrainer and is mounted on the lower plate by four springs and two rubber foam blocks for damping. Underneath the upper plate, an acceleration sensor (ADXL 335 on a GY 61 board) is attached. The lower plate is screwed to the vibration isolated table.
We provide the technical drawings and CAD files for the sensor platform:
Animal restrainer¶
The animal restrainer has to hold the animal during the measurement. The restrainer should be designed, so that the animal is not able to turn around, and that the restrainer does not cause acoustic distortions.
In our setup, we use an animal restrainer made out of an acrylic tube (length x inner diameter, small: 102mm x 27mm (for mouse, cap: cap_small.stl), middle: 137mm x 37mm (small gerbil, cap: cap_normal.stl), big: 137mm x 42mm (big gerbil, cap: cap_big.stl) covered with a wire mesh at the front end and a plastic cap (custom 3D print) at the rear end.
List of all components¶
Component |
Model |
Cost |
Link |
|---|---|---|---|
Anechoic chamber |
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Vibration isolated table |
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PC |
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Soundcard |
Asus Xonar Essence STX II |
310.00 € |
https://www.amazon.com/Xonar-Essence-STX-II-7-1/dp/B00JF6RO7C |
Amplifier (pre-stimulus) |
Amp 74, Thomas Wulf, Frankfurt |
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Amplifier (startle-stimulus) |
Amp 75, Thomas Wulf, Frankfurt |
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Pre-stimulus speaker |
Canton Plus XS.2 |
71,00 € |
https://www.elektrowelt24.eu/shop/product_info.php?refID=20123&products_id=486 |
Startle-stimulus speaker |
Neo-25s, Sinuslive |
44,00 € |
https://www.amazon.de/Sinuslive-13496-Neo-25S-Hocht%C3%B6ner-Black/dp/B003A67KTK |
Data acquisition card |
PCIe-6320, National Instruments |
625.00 € |
|
Breakout box |
BNC-2110, National Instruments |
445.00 € |
|
Sensor platform |
Own construction |
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Acceleration sensor |
ADXL 335 on a GY 61 board |
4.20 € |
http://www.robotpark.com/GY-61-DXL335-3-Axis-Accelerometer-Module |
Animal restrainer |
Acrylic tube 3D printed cab |
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Wire Mesh |
Driller 16910; 1.4 x 1.4 mm |
4.71 € |
|
Springs |
Febrotec 1.4310 d=0.50 Da=11.50 L0=22.40 c=0.075 |
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Cables |