Product Details

SV-1 Voice Key

from £308.47 / €353.19
Quick Overview

SV-1 is a device designed specifically for experiments requiring a vocal response.

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Acquire vocal reaction times with peace of mind.

SV-1 is a device designed specifically for experiments requiring a vocal response. SV-1 monitors the participant’s voice level at all times and when the level rises above a user-specified threshold it reports this to the computer. SV-1 is powered by an 18 MHz microprocessor and is a 100% digital device.

  • Compatible with E-Prime, Presentation, SuperLab and a few others (see list below)
  • Open source C++ and Python libraries available
  • Six TTL lines available for sending event markers. The built-in Accessory Connector provides six lines of I/O (input/output). Each line can individually be configured as either input or output.
  • Serial and a parallel ports for maximum connectivity. USB support can be added via an inexpensive USB-serial port adaptor (see price List).
  • SV-1 comes with a microphone headset and a one year full warranty which covers all parts and labour.
  • AC adapter is optional and battery is included


  • SuperLab: Published by Cedrus; built-in support
  • E-Prime By PST Inc: Emulates a PST Serial Response Box
  • Inquisit: Built-in support
  • EyeLink: Experiment Builder Built-in support
  • Presentation: Cedrus provides a plug-in for Presentation


Cedrus has developed free, open source libraries for:

  • C++
  • Python

Frequency Response

The analog frequency response is fairly flat over the range of 50Hz to 10kHz. That signal is rectified and filtered and the resulting envelope is used to trigger SV-1.

The majority of the low frequency response is determined by the delay setting, e.g. 1kHz signal has a period of 1ms, yet it needs to be relatively immune to ‘P’ and ‘B’ sounds.

SV-1 uses an RS-232 serial port. A free USB-to-serial port adapter is included with every purchase. The adapter requires the installation of a USB driver.

On Mac: the USB driver can be downloaded from the Cedrus website.

On Windows: the USB driver is included with all versions of Windows starting with Windows XP with Service Pack 3.

SV-1 Voice Key

SV-1 Smart Voice Key £ 308.47 353.19

All prices exclude VAT and shipping

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