NTi Audio TalkBox includes a high-precision broadband loudspeaker. Perfect flatness of ±1 dB over the relevant frequency range and highest quality requirements are guaranteed by an individual equalization and calibration using advanced FIR filtering and DSP technology. The radiation characteristic complies with ITU-T P.51 in wide ranges.
Adjusted Output Level
The IEC 60268-16 standard specifies a sound pressure level for a speaker simulator of 60 dBA in 1 meter distance. The TalkBox output levels are calibrated to comply with this standard. To avoid operating failures the TalkBox has no volume control.
The human voice tends to be raised in level in emergency situations. In order to cope with this so called Lombard effect, all STIPA related signals are additionally offered at an increased level of 70 dBA at 1 meter.
Balanced Line In / Out
Using the balanced line out, the TalkBox operates as a signal generator. Sampling frequency deviations – a dangerous trap when using portable CD players for STIPA measurements – are completely eliminated. Any external signal can be connected to the system using the balanced line input. The applied signal is transparently looped to the line output and processed in the internal DSP in real-time to appear equalized at the speaker.
Different Test Signals
The TalkBox also generates additional wave forms: White noise, pink noise, sine wave, reference speech signals and the delay time measurement chirp. Custom designed signals may be loaded onto the CF Card and are seamlessly looped.
Mic Stand Mount
Typically the NTi Audio TalkBox is positioned on a conventional mic stand in front of the talker’s microphone; exactly at the position of the actual talking person during the announcements. The TalkBox features a mic stand mount on the bottom plate.
For measuring speech intelligibility in large buildings the remote mute functionality of the TalkBox is of great help. Any external switching device may be connected to the mute input, allowing e.g. a cell phone controlled ON/OFF functionality. Thus the STIPA test signal might be muted between measurements.
Universal Power Supply
The TalkBox supports a power supply range 10 – 18 VDC. An external power supply for worldwide operation is included. Alternatively the optional battery pack might be used.