XID Voice Key Features

A microphone voice key device is intended to measure a participant’s vocal reaction time. It monitors the volume level on a microphone, and when that volume rises over a certain threshold and stays over that threshold for a certain amount of time (a rise delay or sensitivity), it reports or stores the participant’s reaction time.

An XID voice key device also monitors how long the volume remains above the threshold and then reports the duration. The duration is subject to a drop delay parameter, i.e. how long the volume must stay below the threshold before we conclude that the participant’s response has ended. It is the inverse of a rise delay.

Command	Send Bytes	What Happens:
Set Voice Key Threshold	b1 + value	Sets the voice key threshold. The parameter is a single byte value and should range between "Threshold Pot Minimum Value" (command b6) and "Threshold Pot Maximum Value" (command b7). Locking Level 1 must be set for this command to work.
Set Rise Delay	b2 + value	Sets the voice key rise delay value in milliseconds. The parameter is a single byte and should range between "Delay Pot Minimum Value" (command b4) and "Delay Pot Maximum Value" (command b5). Locking Level 1 must be set for this command to work.
Set Drop Delay	b3 + value	Sets the voice key drop delay value in milliseconds. The parameter is a single byte.
Set Delay (Sensitivity) Pot Minimum Value	b4 + value	Sets the minimum value, in milliseconds, of the delay potentiometer. The parameter is a single byte. Factory default is 0.
Set Delay Pot Maximum Value	b5 + value	Sets the maximum value, in milliseconds, of the delay potentiometer. The parameter is a single byte. Factory default is 100.
Set Threshold Pot Minimum Value	b6 + value	Sets the minimum value of the threshold potentiometer. The parameter is a single byte. Factory default is 0.
Set Threshold Pot Maximum Value	b7 + value	Sets the maximum value of the threshold potentiometer. The parameter is a single byte. Factory default is 255.
Turn Microphone Vu Meter Mode	b8 + value	An ASCII value of 1 causes SV-1 to send the value of the microphone every 30 or 40 milliseconds. A value of 0 stops it.
Get Current Microphone Value	b9	The XID device returns the current microphone value (1 byte?).

Most of the commands in the table above have a corresponding inquiry command to retrieve the voice key settings:

Command	Send Bytes	What Happens:
Get Voice Key Threshold	_b1	Returns voice key threshold value
Get Rise Delay	_b2	Returns the voice key rise delay value in milliseconds
Get Drop Delay	_b3	Returns the voice key drop delay value in milliseconds
Get Delay Pot Minimum Value	_b4	Returns the minimum value, in milliseconds, of the delay potentiometer
Get Delay Pot Maximum Value	_b5	Returns the maximum value, in milliseconds, of the delay potentiometer
Get Threshold Pot Minimum Value	_b6	Returns the minimum value of the threshold potentiometer
Get Threshold Pot Maximum Value	_b7	Returns the maximum value of the threshold potentiometer
Get Vu Meter Mode	_b8	Returns whether vu meter mode is on or off