OPERATING MANUAL

NTi Audio TalkBox

Contact NTi Audio at

Headquarter+423 239 6060
Americas		+1 503 684 7050		
China		
+86 512 6802 0075		
Czech		
+420 2209 99992		
France		+33 4 78 64 15 68		
+49 201 6470 1900		
Germany		
Japan		
+81 3 3634 6110		South Korea		
+82 2 6404 4978		
United Kingdom+44 1438 870632		

info@nti-audio.com
americas@nti-audio.com
china@nti-audio.com
czech@nti-audio.com
france@nti-audio.com
de@nti-audio.com
japan@nti-audio.com
korea@nti-audio.com
uk@nti-audio.com

www.nti-audio.com

NTi Audio AG
Im alten Riet 102, 9494 Schaan
Liechtenstein, Europe
is an ISO 9001:2015 certified company.

© NTi Audio AG
June 2023
All information subject to change without notice.
©
All rights reserved.
®
Minirator is a registered trademark of NTi Audio.
™
XL2, EXEL and TalkBox aretrademarks of NTi Audio.
2

Made in
Sw i t ze r l a n d

Index:
1. Introduction�������������������������������������������������������������������������������������������������������� 4
2. Overview������������������������������������������������������������������������������������������������������������� 5
General������������������������������������������������������������������������������������������������������������� 6
NTi Audio TalkBox Controls������������������������������������������������������������������������������� 7
Side & Rear Panel������������������������������������������������������������������������������������������� 13
3. How to use the NTi Audio TalkBox������������������������������������������������������������������ 14
Procedure������������������������������������������������������������������������������������������������������� 14
Output Level��������������������������������������������������������������������������������������������������� 14
Lombard Effect����������������������������������������������������������������������������������������������� 15
CF-Card����������������������������������������������������������������������������������������������������������� 16
My Own Files������������������������������������������������������������������������������������������������� 17
4. Battery Operation �������������������������������������������������������������������������������������������� 18
5. Related Products���������������������������������������������������������������������������������������������� 19
6. Further Information������������������������������������������������������������������������������������������ 20
Registration����������������������������������������������������������������������������������������������������� 20
Warranty Conditions��������������������������������������������������������������������������������������� 21
Service and Repairs���������������������������������������������������������������������������������������� 21
Warnings��������������������������������������������������������������������������������������������������������� 22
Calibration Certificate�������������������������������������������������������������������������������������� 22
CE Declaration of Conformity������������������������������������������������������������������������� 23
7. Technical Data TalkBox������������������������������������������������������������������������������������� 24

3

1. Introduction
Congratulations and thank you for buying NTi Audio’s TalkBox, a product speciallysuited as test signal source for speech intelligibility measurements. This product provides, in combination with an NTi Audio Acoustic Analyzer, the all-in-one solution forfast and comprehensive STIPA testing of a complete public announcement system.
Additionally, various other test signals are supported for further test applications.
We are convinced you will enjoy using it!
This manual describes the NTi Audio TalkBox operation and functions in detail. Further application information can be found on the web site.

The NTi Audio TalkBox product package includes the following items:
•
•
•
•
•
•

4

NTi Audio TalkBox
Protection Cover mounted with NTi Audio lanyard
CF-Card with test signals & individual calibration data
Mains Power Supply & Power Cord
Carrying PouchUser Manual

2. Overview
NTi Audio TalkBox greatly simplifies the acoustical feed of the STIPA intelligibility
test source signal into closed sound reinforcement systems. It presents the standardized voice-like acoustical signal emission simulating a human talker according
to IEC 60268-16 at standardized levels.

NTi Audio TalkBox
5

GeneralNTi Audio TalkBox features human head-like dimensions. A build-in combinationof solid-state generator and DSP ensures highest playback accuracy and lowest
sample frequency deviations with minimized jitter effects. The internal precision
loudspeaker is individually calibrated to achieve a very flat frequency response in
the typical frequency range of the human voice. Each TalkBox is individually equalized and calibrated and has an excellent frequency response accuracy of +/- 1 dBover the relevant frequency range. The radiation characteristic complies with the
ITU-T P.51 in wide ranges.
The perfect frequency response and the precisely correct playback sampling rate
are specifically important to minimize systematic errors when performing STIPA
measurements.

Speaker
The IEC60268-16 standard specifies a sound pressure level for a speaker simulatorof 60 dBA in 1 meter distance. The NTi Audio TalkBox levels are calibrated to comply
with this standard. To avoid operating failures the TalkBox has no volume control.

Mic Stand Mount
The exact positioning the NTi Audio TalkBox in front of a microphone (at the place
where a real human speaker would be) is easy using a conventional mic stand. A
universal mic stand mount is available at the bottom of the box.

6

2

3

NTi Audio TalkBox Controls
Output Mode Selector

CF CardOutput Mode

Mute LineOut

Power LED

Line In

Line InCF CardSelectTrack

Line Out

Play

Line Out

Clip

Select Track Switch

Play LED

Clip LED

NTI Audio TalkBox Controls
Alle Masse in mm

Tolerance:+-0.1mm

Scale: 1 : 1
Weight:Material: Alu 1,5mm, zum eleoxieren ge

Oberfläche:Schwarz eloxiert

THIS DRAWING IS THE EXCLUSIVE PROPERTY OF NTI AG - WITHOUT THEIR WRITTEN CONSENT IT IS NOT PERMITTED TO BE COPIED OR GIVEN T

1

Output Mode Selector 2
The output
selector switch offers the following threemodes:
LineIn
Output Mode
CF Card

3
Line OutThe audioSelectsignal is available at the Line
speaker
and theIn
Mute LineOut
Output ModeLine LineOut Out.
CF Card
Track
Play
Clip
The audio
signalOut
Line
In at Line
Select signal is muted (noMute LineOut
Output ModeLine
Outand speaker).
CF Card
Track
Play
Clip
Mute LineOut

The audio signal is available at the Line Out. The speaker amplifier is
Select
Track
Play
Clip
muted.
Alle Masse in mm

Tolerance:+-0.1mmOberfläche:Schwarz eloxiert

Scale: 1 : 1
Weight:Material: Alu 1,5mm, zum eleoxieren geeigne

7

THIS DRAWING IS THE EXCLUSIVE PROPERTY OF NTI AG - WITHOUT THEIR WRITTEN CONSENT IT IS NOT PERMITTED TO BE COPIED OR GIVEN TO THIRPower LED
The red Power LED indicates the following:

fast
flashing
continuouslyonslow
flashing

8

The power up sequence is in process (about 10 seconds)

The TalkBox is powered on and ready for operation.

The outputs are muted by• the Output Mode Selector or• the External Mute Input

CF-Card
The supplied CF-Card needs to be pushed into the provided slot. Up to 15 test signals can be stored on the CF-Card. The size of the test signals is as big as required
for the looped operation. The selected signal is further processed and seamlessly
looped by the built in DSP. The CF-Card is FAT32 formatted and can be read/written
by any PC/MAC with CF-Card reader. The TalkBox repeats the selected audio trackas long as mains power is connected. Besides the STIPA test signal the CF-Card
contains the following additional wave forms:
CF-Card Track List:
1

STIPA (Standard, edition 5)

60 dBA @ 1 m

2

Pink Noise

60 dBA @ 1 m

3White Noise

60 dBA @ 1 m

4Sine 1 kHz

60 dBA @ 1 m

5Male Speaker (German)

60 dBA @ 1 m

6

Male Speaker (English)

60 dBA @ 1 m

7

Delay Test Chirp

8

Fast Pink Noise 1 sec

60 dBA @ 1 m

9Fast Pink Noise 4 sec

60 dBA @ 1 m

A

STIPA (Lombard, edition 5)

70 dBA @ 1 m

B

Pink Noise

70 dBA @ 1 m

C

White Noise

70 dBA @ 1 m

DSine 1 kHz

70 dBA @ 1 m

EMale Speaker (German)

70 dBA @ 1 m

FMale Speaker (English)

70 dBA @ 1 m

9Any hot swap of the CF-Card is not supported. In case the CF-Card
has been removed during operation it shall be returned and themains power shortly disconnected to initiate the operation again.

File format of audio signals• *.wav file
• Sample rate: 44100 Hz• Mono• 16 Bit• PCM linear quantization
File name format
The first character of wav-file name matches the output selector switch position.
So, the audio files names are e.g. “1anyName.wav” or “8anyName.wav”, whereby“anyName” may describe the content of the wav-file for example “1_STIPA.wav”.
The maximum length of the filename is 8 digits, e.g. “xxxxxxxx.wav”.
Calibration data
The CF-Card keeps additionally the individual calibration data of theNTi Audio TalkBox. The file is named “xxx.cal”. The CF-Card is labeled with the serial
number of the corresponding TalkBox, so the CF-Card and the NTi Audio TalkBox dohave the same serial number, guaranteeing accurate and calibrated operation.

The serial number on the CF-Card must match with the serial number of the NTi Audio TalkBox, otherwise the acoustical parameters of
the TalkBox are out of specifications.

10Play LED
The green Play LED indicates the following:

continuouslyon• The audio signal is replayed• At Line In mode (= Select Track switch set to “0”) and input
signal > -30 dBu

flashing

Error indication, which might be caused by• The CF-Card is not plugged in or damaged• The file “serialnumber_xxx.cal” is not found on the card
• The selected audio file is not available, damaged or of wrong
formatSelect Track Switch
This switch allows the following selections:“0”This position selects the input signal from the input connector“Line In” to the speaker.

“1” - “F”

These positions select the individually stored audio tracks fromthe CF-Card in hex-order form (1, ... , 9, A, B, C, D, E, F).

Clip LED
The red Clip LED is activated when the Line In mode is selected(= Select Track switch set to “0”). Reduce the input level when the Clip LED flashes.

11Line InXLR input connector for external audio signals.
The Line In mode (Select Track switch = “0”) enables to play an external audio signal with the NTi Audio TalkBox. In the Line In mode the Play LED indicates an input
signal > -30 dBu and the Clip LED is activated at input signals > +15 dBu.
The DSP based equalization introduces a signal propagation delay of 59 ms between the Line-In and the acoustical output. Consequently and in order to guarantee synchronicity between the acoustical output and the line-output for delay timemeasurements the latter is also delayed by 59 ms.
Line Out
Using the balanced line out, the TalkBox operates as a signal generator. The stored
signal of the CF-Card or any connected signal from the Line In connector is directly
send to the Line Out connector (not equalized).

12

Side & Rear Panel

External Mute Input
Type Plate

DC
In
Serial Number
NTi Audio TalkBox Side View & Type Plate

External Mute Input
The External Mute Input provides the possibility to mute the NTi Audio TalkBox froma remote position, such as by using a mobile phone or radio control devices. Closing an external switch connected with this 3.5mm jack connector (connecting tip &ring) will mute the audio signal equally to the output selector switch in mute position. This feature is of great help e.g. at STIPA measurements in large buildings.

13

3. How to use the NTi Audio TalkBox
Using the NTi Audio TalkBox as acoustical test source for STIPA measurements
provides two major advantages:• Extended test coverage• Easy to handle test signal injection
The human head sized NTi Audio TalkBox replaces and simulates a real speaker
when measuring speech intelligibility. Such a setup considers the entire signal path
including the used microphone, the acoustical characteristics of the speaker’s cabinand existing background noise.

Procedure• Position the NTi Audio TalkBox at the typical speaker position in front of the
speaker’s microphone.
• Connect the external power supply. After approx. 10 seconds the startup process
is completed and the NTi Audio TalkBox is ready for operation.
• Selected the required track number with the Track Selection Switch.
• Output Mode: Set the selector switch to• Speaker for acoustical output• LineOut for electrical output signal or• Stop the signal using the Mute position.

Output Level
The output level of the provided standard STIPA test signals is 60 dBA @ 1 m distance to the speaker. Additionally, further test signals at other levels are provided,
please see the CF-Card Track List for details.
14Lombard EffectAt increasing environmental noise the human persons speaking into the microphone at PA systems gradually increase the sound pressure level of their speech.
The standardized speaking level is 60 dBA. Our ears recognize a speaking level increase of 10 dBA as subjective double sound pressure level. To verify the PA system
operating in good order at this physical effect, the following shall be carried out:
• Follow the prior described measurement procedure, using the STIPA test
signal with 60 dBA @ 1m.
• Select the STIPA test signal with 70 dBA @ 1m and verify the operation of the
PA system; no clipping shall occur.

15

CF-Card
We recommend to use original CF-Cards, NTi Audio # 600 000 087, only. Other CFCards may not be compatible with the NTi Audio TalkBox, thus e.g. wav-files are
not replayed. For operation the calibration file xxx.cal has to be copied on a new
CF-Card. You may format the CF-Card as follows:• Connect the CF-Card to the PC, the card is recognized e.g. as letter “z”.
• Select “Run…” from the Windows Start menu, see picture below.
• Insert the term: format z: /fs:FAT32 /a:4096 /x• The CF-Card is formatted to FAT32 with 4096 byte cluster size and can now
be used with the NTi Audio TalkBox.

Format CF-Card
16

My Own Files
You can load your own audio files onto the CF-Card and replay with theNTi Audio TalkBox. Kindly observe the following details:
Do not delete the calibration data file labeled “xxx.cal“!
The NTi Audio TalkBox requires the calibration data to meet the product specifications.
File format of audio signals• *.wav file
• Sample rate: 44100 Hz• Mono• 16 Bit• PCM linear quantization
File name format
The first character of the wav-file name matches the output selector switch position. So, the audio files names are e.g. “nr_anyName.wav”, whereby “nr” is the TalkBox selection switch position and “anyName” describes the content of the wav-filefor example “9_myfile1.wav” or “A_myfile2.wav” - “F_myfile3.wav”. The maximum
length of the filename (=anyName) are 8 digits.
Level
The test signal level shall be physically tested by using an NTi Audio Acoustic Analyzer and the source data adjusted to requirements.
LengthThe minimum length of your wave file is 100ms.

17

4. Battery Operation
The TalkBox may be operated with a battery pack (non NTi Audio product) for mains
power independent operation.
Use of a battery pack
Connect the DC output of the battery pack with the DC input of the TalkBox. As
soon as the connection is established, the NTi Audio TalkBox starts running. For
storage or when not used for a longer period of time, please disconnect the battery
cable preventing the complete discharging of the battery.
Recommended battery packs
The following in Europe available battery pack has been verified and approved:• XTPower XT-16000QC3 PowerBank
ExampleA battery with 39 Watt hours offers the following typical running time
Idle mode:		Standby, Electrical output:		
15 hours
STIPA:				
Output on (60dBSPL)		
12 hours
STIPA Lombard:		
Output on (70dBSPL)		
7 hours18

5. Related Products
XL2 Audio and Acoustic Analyzer
The XL2 analyzer forms the unique combinationof a state-of-the-art Sound Level Meter, a comprehensive Acoustical Analyzer as well as a powerful Audio Analyzer. The wide range of functionalities are tailored for challenging applications in
Installations, Live Sound, Studio, Broadcast andEnvironmental Noise measurements.
Measurement microphones are available foracoustical measurements. The microphones are
48V phantom powered and include an electronic data sheet. The Automated Sensor Detection(ASD) of the XL2 Analyzer automatically reads
this data, i.e. the microphone model and calibration data. This promotes faster setup and ensures accurate measurements.

STIPA Measurement Option for XL2
The STIPA analyzer option allows the reliablemeasurement of the speech transmission index
according to the latest IEC standards within 15
seconds. Besides the single value STI or CIS test
result, a detailed view of the modulation indicesand individual band level results is provided.

19

6. Further Information
Registration
Register your instruments at My NTi Audio and benefit from the following possibilities:• Free updates for your instruments• Activation of optional product functions• Premium access to downloads• Receive application and product news
• Faster worldwide support• Tracing support in case of loss or theft• Calibration support

How to Register• Open the web page “https://my.nti-audio.com”.
• You are prompted to login or create your My NTi Audio account.
• The web page “My NTi Audio Products” opens.
• Select the product type and enter the serial number.
• Confirm with “Register”.
• Now your product is listed in the table “My Products“.

20Warranty Conditions
International warranty
NTi Audio guarantees the function of its products and the individual components
for a period of one year from the date of sale. During this period, defective products
will either be repaired free of charge or replaced.
Limitations
These guarantee provisions do not cover damage caused by accidents, transportation, incorrect use, carelessness, non-original accessories, the loss of parts, operation with non-specified input voltages, adapter types or incorrectly inserted batteries. NTi Audio accepts no responsibility for subsequent damage of any kind. The
warranty will be voided by carrying out repairs or services by third parties who are
not part of an approved NTi Audio Service Centre.
Statutory Rights
Consumers may have legal (statutory) rights under applicable national laws relating to the sale of consumer products. This warranty does not affect your statutory
rights. You may assert any legal rights you have at your sole discretion.

Service and Repairs
If your product is not functioning correctly or is damaged, please contact the local
NTi Audio partner for assistance. If the product needs to be returned for service,kindly follow the service guidelines at www.nti-audio.com/service.

21

Warnings
In order to avoid any problems during the operation of the instrument, follow thenotes listed below:• Remove the transport protection cover prior using the TalkBox.
• The NTi Audio TalkBox includes a high precision electromechanical transducer with open air gap. Dust could degrade the function of this transducer.
Please take care to use and store the NTi Audio TalkBox only in clean environments.
• Read this manual thoroughly prior using this product.
• Use the product for the intended purpose only.
• Do not disassemble the product.
• Never use the product in a damp environment.

Calibration Certificate
Your NTi Audio instrument has been carefully tested during production and corresponds to the specifications listed in “Technical Data”. Calibration certificates for
new products are optional.
NTi Audio recommends annual calibration of the products after the purchase. The calibration provides documented and traceable measurement accuracy and confirms that your NTi Audio product meets or exceeds the
published specifications. The calibration and adjustment procedures follow the documentation and traceability requirements of the standard
EN ISO / IEC 17025.
For calibrations kindly follow the service guidelines at www.nti-audio.com/service.

22

CE Declaration of Conformity
CE / FCC Compliance Statement

		We, the manufacturer NTi Audio AG, Im alten Riet 102, 9494 Schaan, Liechtenstein,
do hereby declare that the product “NTi Audio TalkBox”, released in 2005, conforms
to the following standards:••••

EMC: 2014/30/EU
Harmonized standards: EN 61326-1
Explosive atmospheres (ATEX): 2014/34/EU
Directive 2011/65/EU on the restriction of the use of certain hazardous substances in electrical and electronic equipment (RoHS).
• Directive 2012/19/EU on waste electrical and electronic equipment (WEEE).
This declaration becomes void in case of any changes on the product without written authorization by NTi Audio.

Date:				25. July 2019

Signature:		Position of signatory:		
COO								23

7. Technical Data TalkBox
Standards• IEC 60268-16 (Objective Rating of Speech Intelligibility)• ASTM E1179-13 (Sound Sources for Testing Open Office)Waveforms• Up to 15 different signals• Waveforms can be added / changed by the user
Factory signal set• NTi Audio STIPA Test Signal, Reference Speech Signal• White Noise (crest factor, PAR* = 3.55 (11.0 dB))
• Pink Noise (crest factor, PAR* = 3.55 (11.0 dB))
• Fast Pink Noise 1 sec (crest factor, PAR* = 4.22 (12.5 dB))
• Fast Pink Noise 4 sec (crest factor, PAR* = 4.47 (13.1 dB))
• Delay Test Signal• Sine 1 kHz

Line Out• XLR, balanced 100 Ohm, unbalanced 50 Ohm• Maximum output level: +18 dBu,
1 kHz file with 60 dB @ 1 meter: typically -11 dBu

Line Input• XLR, balanced 38 kOhm
• Max. input level: +18 dBu (acc. to EBU R68, ITU-R rec. 645)
• Internal delay from XLR input to speaker: 59 ms

CF-Card• min. 512 MB included, FAT32, NTi Audio # 600 000 087• Wav-file format: 16 Bit, 44.1 kHz mono

Acoustical Flatness

STIPA band levels (in axis):				• typ < +/- 0.5 dB @ 24°C
• typ < +/- 1.0 dB @ 10°C - 30°C

Acoustical Output Level • STIPA: 60 dBA @ 1 m +/- 0.5 dB, acc. to IEC 60268-16• STIPA band sensitivity gradient: - 0.07dB / °C (average)• Others see track list in user manual
Power Supply• 9 - 17 VDC, 10 Watt
• External switching power supply included (110 V ... 240 V)

External Mute

• Jack 3.5 mm (1/8“), tip & ring
• Floating switch required

Mounting

Mic Stand 5/8” with Adapter to 3/8”

24

Dimensions (LxWxH)

150 x 150 x 175 mm (5.9 x 5.9 x 6.9 inch)

Weight3.5 kg (7.7 lb)

Operating Temperature

0° to +45° C (32° to 113° F)

Protection Rating

IP51

Included Accessories

Mains Power Adapter, CF Card and Soft Carrying Case

* PAR = peak-to-average ratio

Sound Pressure Level dBZ @ 1 m

Typical Frequency Response @ Broadband Level 60 dBA+/-1 dB Tolerance

54.0

53.0

52.0

51.0
125 Hz250 Hz500 Hz

1 kHz

2 kHz

4 kHz

8 kHz

Frequency

25

70Sound Pressure Level dBZ @ 0.5 m

69
68+/-1 dB Toleranz

67
66
65
64
63
62
61
60
10 Hz

100 Hz

1 kHz
Frequenz

26

10 kHzPolar Plots (6 dB/div)

27

28

29

30

31

32

33

34

You may stick this table onto your NTi Audio TalkBox:

1

STIPA (Standard, edition 5)

60 dBA @ 1 m

2

Pink Noise

60 dBA @ 1 m

3White Noise

60 dBA @ 1 m

4Sine 1 kHz

60 dBA @ 1 m

5Male Speaker (German)

60 dBA @ 1 m

6

Male Speaker (English)

60 dBA @ 1 m

7

Delay Test Chirp

8

Fast Pink Noise 1 sec

60 dBA @ 1 m

9Fast Pink Noise 4 sec

60 dBA @ 1 m

A

STIPA (Lombard, edition 5)

70 dBA @ 1 m

B

Pink Noise

70 dBA @ 1 m

C

White Noise

70 dBA @ 1 m

DSine 1 kHz

70 dBA @ 1 m

EMale Speaker (German)

70 dBA @ 1 m

FMale Speaker (English)

70 dBA @ 1 m

35

500 dt 11. 21