NTi Audio TalkBox User Manual

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Made in Switzerland

AUDIO & ACOUSTIC MEASUREMENT SOLUTIONS

TalkBox

ACOUSTIC GENERATOR - STIPA REFERENCE

STIPA REFERENCE IN ACC. WITH IEC 60268-16

SYSTEM LINE-UP

PRECISE FLATNESS

CALIBRATED LEVEL

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Introduction

The TalkBox is an active acoustic signal generator for speech intelligibility measurements of

evacuation and announcement systems, as well as for level alignment of teleconference or

any audio system incorporating a microphone input. In combination with the XL2, it facilitates

complete end-to-end evaluation of the speech intelligibility STIPA from the talker’s microphone

to the listeners’ ears.

The TalkBox simulates a human talker (60 dBA @ 1 meter according to the IEC 60268-16 stan-

dard) with the STIPA test signal and spoken messages. Further it provides a wide range of test

signals like sine, pink noise, white noise and delay.

The TalkBox features human head-like dimensions and is based on a solid-state generator. It replays

the STIPA test signal with a precise frequency response, individually equalized for each TalkBox, also

ensuring best performance through the internal ampliﬁer and the preci-

sion loudspeaker. A variety of supplied or user-deﬁned test signals may

be faithfully reproduced for different alignment application areas.

Application Areas

Evacuation System Commissioning

Installed Sound System Calibration

Classroom testing

AV Installations

TalkBox

Portable and easy to operate

CF Card containing

Test Signals & Calibration Data

DC Input Remote Mute Input

Stand Mounting Adapter

Power Amplifier and Signal Processor

How can a TalkBox help you?

The TalkBox is a professional tool that simpliﬁes STIPA measurements. It com-

bines sound samples, an ampliﬁer, and a loudspeaker into a lightweight, human-

head-sized box. It delivers the built-in equalized acoustic test signals at exactly

the levels speciﬁed by the standard. Pop it onto a microphone stand to position

it where the mouth of the human speaker would normally be.

The NTi Audio TalkBox removes the uncertainties and reduces your effort, as

it is designed precisely for this use; it assists you in testing the entire signal

path, including the microphone and the acoustic environment. Also, the Line

Out connection may be used to inject test signals into systems which do not

include an announcement microphone.

Testing the whole signal chain

The TalkBox, together with the XL2 Acoustic Analyzer, are used to test the entire signal chain

from the speaker's mouth to the listeners' ears, considering the acoustic environment of both

the sending and the receiving rooms.

Acoustic Input

Microphone

(Frequency Response & Distortion) Room Acoustics Background Noise

Audio Processing

Distortion Noise Limiter Amplifier

Acoustic Output / Distribution

Speakers

(Frequency Response & Distortion) Room Acoustics Background Noise

Calibrating Conference Systems

Teleconference systems play a significant role in today’s connected world, allowing companies to communicate

seamlessly across continents. Proper system alignment, delivering consistent speech levels and excellent intel-

ligibly is a key success factor for the installing company.

The conference participants expect that they be allowed to concentrate on the business top-

ics at hand and not be distracted by any inadequacies or failures in the communication system.

NTi Audio equipment provides you with the tools to align the systems and rooms with excellence and confi-

dence.

The NTi Audio TalkBox simplifies and improves the setup of microphones, system levels and equalization. It

generates a reference human speech signal or other standard audio test signals, so that entire conference sys-

tems can be adjusted by a single person. Additional test signals support the determination of system flatness

and response effects e.g. in teleconference applications.

The TalkBox generates all test signals for professional conference room setup. Typically the TalkBox is placed

at measured reference points, those being each anticipated speaking position in the room. The XL2 then objec-

tively measures speech intelligibility at the different listening positions.

The TalkBox is also often used to objectively determine the intelligibility of speech in rooms where no amplifica-

tion system is used, such as in classrooms. In this case only the acoustic environment is tested. The TalkBox is

placed at the teacher's usual speaking position while the XL2 objectively measures speech intelligibility at the

different student positions.

Essential TalkBox features

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10 100 1000 10000 100000

Typical Frequency Response (meets the specified ±1 dB tolerance band IEC 60268-16 requirement)

Level [dB]

Frequency [Hz]

Individually Equalized

The NTi Audio TalkBox includes a precision broadband

loudspeaker. Precise flatness of ±1 dB over the relevant

frequency range and the highest reproduction quality are

guaranteed by individual equalization and calibration using

Standard and Custom Signals

The TalkBox also generates additional waveforms; white

noise, pink noise, sine wave, reference speech signals and

the delay time measurement chirp. Custom signals may be

loaded onto the CF Card and are seamlessly looped.

advanced FIR filtering and DSP technology. The radiation

characteristic complies with ITU-T P.51 in wide ranges.

Calibrated Output Level

The IEC 60268-16 standard specifies a sound pressure le-

vel for a speaker simulator of 60 dBA at 1 meter distance.

The TalkBox output levels are calibrated to comply with

this standard. To avoid operating failures the TalkBox has

Lombard Effect

Human voices tend to rise in level in emergency situations.

In order to reproduce this so-called Lombard effect, all

STIPA-related signals are additionally available at an in-

creased level of 70 dBA at 1 meter distance.

no volume control.

Balanced Line Out

Using the balanced Line Out, the TalkBox operates as an

audio signal generator. Deviations in sampling frequency

- a dangerous trap when using CD players for STIPA mea-

surements - are eliminated.

Balanced Line In

Any external signal can be connected to the system using

the balanced Line In. The signal is simultaneously looped

to the Line Out and reproduced through the internal DSP

to the loudspeaker.

Universal Power Supply

The TalkBox supports a power supply range of 10 - 18

VDC. An external power supply for worldwide operation is

included.

Technical Specifications

TalkBox

Waveform

Line Out

Line In

CF Card

Acoustical Flatness

· Up to 15 different signals

· Waveforms can be added / changed by the user

· Factory signal set: NTi Audio STIPA Test Signal, Reference Speech Signal, Sine 1 kHz, White Noise, Pink Noise, Delay Time Chirp

· XLR, balanced 100 W, unbalanced 50 W

· Maximum output level: +18 dBu

· XLR, balanced 38 kW

· Maximum input level: +18 dBu

· Internal delay XLR input to speaker: 59 ms

· 256 MB included, FAT32 formatted

· Wave ﬁle format: 16 bit, 44.1 kHz mono

· STIPA band levels (on-axis)

· typ. < ±0.5 dB @ 24°C

· typ. < ±1.0 dB @ 10°C – 30°C

Acoustical Output Level

Power Supply

External Mute

Mounting

Dimensions

Included Accessories

Weight

· STIPA: 60 dBA @ 1m ± 0.5 dB, acc. IEC60268-16

· STIPA band sensitivity gradient:

- 0.07 dB / °C (average)

· Others see track list in user manual

· 10 - 18 VDC, 10 W

· External switching power supply included (for worldwide usage 100 V .. 240 V)

Jack 3.5 mm (1/8") Floating switch required

· Mic Stand 5/8" with Adapter to 3/8"

· L x W x H: 150 x 150 x 175 mm (5.9 x 5.9 x 6.9 inch)

· Mains Power Adapter

· CF Card

· Soft Carrying Case

· 3.5 kg

NTi Audio TalkBox User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual