• Better speech intelligibility   • Testing entire signal chain   • Voice evacuation systems   • Setting conference rooms   • Calibrated acoustic source

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. It allows for the complete end-to-end evaluation of the speech intelligibility STI-PA from the talker’s microphone to the listener’s ears. The TalkBox provides the test signal simulating a human talker at 60 dBA @ 1 meter according to IEC 60268-16.

The TalkBox features human head-like dimensions and is based on a solid-state-generator. It replays the STI-PA test signal at the precisely correct playback sampling rate, also ensuring best performance through the internal amplifier and the precision loudspeaker. A variety of supplied or user-defined test signals may be precisely output for different alignment applications.

TalkBox Rear Panel View

NTi Audio TalkBox Features

Individually Equalized NTi Audio TalkBox includes a precise 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.

Lombard Effect Human voice tends to be raised in level at emergency situations. In order to cope with this so called Lombard effect, all STI-PA 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 STI-PA 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 speaker microphone; exactly at the position of the actual human speaker during the announcements. The TalkBox features a mic stand mount on the bottom plate. Remote Mute 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 building e.g. a cell phone controlled ON/OFF functionality. Thus the STI-PA 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.

Schematics