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20 July 2024
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NTI TALKBOX ACOUSTIC GENERATOR STIPA source, without calibration certificate

Stock code
NTI (NTI Audio)
Model number
NTI TALKBOX ACOUSTIC GENERATOR STIPA source, without calibration certificate
Typical Applications of the TalkboxNTI TALKBOX ACOUSTIC GENERATOR STIPA source, without calibration certificateNTI TALKBOX ACOUSTIC GENERATOR STIPA source, without calibration certificateNTI TALKBOX ACOUSTIC GENERATOR STIPA source, without calibration certificateNTI TALKBOX ACOUSTIC GENERATOR STIPA source, without calibration certificateNTI TALKBOX ACOUSTIC GENERATOR STIPA source, without calibration certificate



The TalkBox is an acoustic signal generator for speech intelligibility measurements in evacuation and announcement systems, as well as for level alignment of teleconference and other audio systems. The powered precision loudspeaker allows for the complete end-to-end evaluation of the speech intelligibility, STIPA, from the speaker's microphone to the ears of the listener. Additional waveforms are available, including noise and delay 'chirp' signals. The user may load custom signals to a CF card and play them back in a seamless loop. A balanced line input and output are also available.

The TalkBox provides a test signal simulating human speech at 60dBA at 1 metre according to IEC 60268-16. To avoid operating errors, the unit has no volume control. The human voice tends to be raised in level in emergency situations. In order to cope with this 'Lombard' effect, all STI PA related signals are additionally offered at an increased level of 70 dBA at 1 metre. It also generates white and pink noise, 1kHz sine wave, reference speech signals and the delay-time measurement chirp.

Using the balanced line out, the TalkBox operates as a signal generator. Sampling frequency deviations, a potential issue 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 feed, equalised, the loudspeaker.

The TalkBox has human head-like dimensions; typically it is positioned on a conventional microphone stand in front of the announcement microphone, exactly at the position of the actual human speaker during the announcements. There is microphone stand thread on the bottom plate.

The design is based on a solid-state generator; it replays the STIPA test signal at the precisely correct playback sampling-rate, also ensuring best performance through the internal amplifier and the precision loudspeaker. Flatness of +/- 1dB over the relevant frequency range and highest quality requirements are guaranteed by individual equalisation and calibration using advanced FIR filtering and DSP technology. The radiation characteristic complies with ITU-T P.51 in wide ranges.

When measuring speech intelligibility in large buildings the remote mute function is convenient. Any external, floating, switching device may be connected to the mute input, thus the STIPA test signal may be muted between measurements. The TalkBox supports a power supply range of 9-18V DC. An external power supply for worldwide operation is included. Alternatively the optional battery pack may be used.

Line input: +18dBu maximum, 38k ohms, balanced 3-pin female XLR.
Delay: 59ms, from connector to loudspeaker.
Line output: +18dBu maximum, 100 ohms, balanced 3-pin male XLR.
Output level: -11dBu from 1kHz file giving 60dBA at 1metre.
Acoustic output: 60dBA +/- 0.5dB SPL at 1 metre.
Acoustical response: Better than +/- 0.5dB, 24 degrees C, for STI PA band levels 100Hz-10kHz, on axis.
External mute: 3.5mm jack socket.
Power source: 9-18V DC, 10W; In-line power supply included, 100V-240V AC, with IEC inlet.
Dimensions: 150 x 150 x 175mm (l x w x h)
Weight: 3.5kg

Included accessories: 256MB Compact Flash card, bag, AC power supply, power cable.
Optional accessories: Battery pack.

Battery Pack

This Li-ion battery is designed to fit on the side of the TalkBox, fixed by hook-and-loop strips. An integrated charge indicator shows the remaining energy; when fully charged it will power the TalkBox for more than seven hours. The battery is charged using the power supply included with the Talkbox unit, connected with the cables and adapter supplied. The DC output of the battery is disabled during the charge process.

Output voltage: 9V, 2A maximum
Capacity: 48Wh nominal
Running times: 15 hrs, idle mode
12 hrs, STIPA at 60dB SPL
7 hrs, STIPA at 70dB SPL
Dimensions: 153 x 93 x 23 mm
Weight: 400g

Included accessories: Cables and adapter to connect to TalkBox and power supply.

Ordering Note

Unless otherwise stated, all products are exclusive of calibration certificate(s). NTi TalkBox calibration certificates can be purchased optionally along with the product. Please ensure you add multiple calibration certificates if the system you are purchasing includes multiple products.

  Description Price £
ex. VAT
Add to basket
NTI TALKBOX ACOUSTIC GENERATOR STIPA source, without calibration certificate Stock code: 25-681
Ordered on demand, cancellations may incur charges, available in 3‑4 weeks. Need it sooner? Call us
NTI BATTERY PACK For Talkbox acoustic generator, Li-Ion, rechargeable, 9V, 2A max, 48Wh Stock code: 25-684
Discontinued. Please contact Technical Support for alternatives.
NTI CALIBRATION CERTIFICATE For XL2 and other specified NTi products Stock code: 25-618
Ordered on demand, available in 2‑3 weeks. Need it sooner? Call us