In a typical setup a sound source, normally a small loudspeaker, is acting as a talker. The loudspeaker should be placed in the normal position for the talker, either using or not using a public address system as required.
The level should correspond to the normal level for speech, about 60 dB A-weighted 1 m from the sound source. Note that STIPA-method considers the actual received sound level to mimic the threshold of hearing as well as level dependent masking. For some applications, like electrical testing, these features are irrelevant and may be switched off in the set-up of the measurement.
The signal to the loudspeaker is obtained by playing the supplied audio-file (available from www.Norsonic.com/downloads) with the recorded excitation signal.
Place the sound level meter in the place where you want the speech intelligibility to be measured. Press the START button. The measurement will stop automatically after 21 seconds and the estimated STI-value and the corresponding CIS value is indicated on the screen.
Measurement too short