Digital Speech Level Analyser

Gives you the information you need aboutSpeech Performance

• Purpose-designed (not based on a PC sound card)

• 24-bit A-D and D-A conversion technology

• Noise floor lower than -80dBm for balanced input

• Dynamic range greater than 110dB for balanced input (noise floor to clipping)

• The best quality platform available

DSLA: A Precision Instrument

DSLA Speech Quality Display

MOS prediction

Reference surface – transmitted signal

Degraded surface – received signal

Error surface

WirelessNetwork

Hands-free

PC

DSLA

Hands-free

Handset port

Ethernet

Speech Quality Analysis for Handset to Handset Path (Same

Location) Using One DSLA

WirelessNetwork

Hands-free

PC

DSLA

PSTN

Analogue phone line

Handset portPhone line port

Speech Quality Analysis forPSTN to Handset Path

(Same Location), Using One Digital Speech Level

Analyser (DSLA)

WirelessNetwork

DSLA

DSLA

PC

Hands-free

Handset port

PC

Hands-free

Handset port

Speech Quality Analysis forHandset to Handset Path

(Different Locations), Using Two Digital Speech Level

Analysers (DSLA)

PSTNWirelessNetwork

DSLA

DSLA PC

PC

9-18 Vdc input for vehicle use

Hands-free

Phone line port

Handset port Speech Quality Analysis forPSTN to Handset Path

(Fixed & Mobile Locations), Using Two Digital Speech Level

Analysers (DSLA)

Head & Torso Simulator (HATS) and

Associated Components

Handset Testing using Acoustic Test Components and Digital Speech

Level Analyser (DSLA)

Base

Station Emulator

AudioIN OUT

Chamber

Handset Testing using B&K Acoustic Test Components and Digital Speech Level Analyser

(DSLA)

Chamber

Artificial Mouth, 4227

Artificial Eartype 4185 or

4195

PC

DSLA

Handset under test

Mic. Pre-amp.,2690

Power Amp.,2716

Base

Station Emulator

AudioOUT IN

Head & Torso Simulator (HATS) and

Associated Components

Handset Testing using Acoustic Test Components and Digital Speech

Level Analyser (DSLA)

Base

Station Emulator

AudioIN OUT

Chamber or vehicle

Hands-free kit

Head & Torso Simulator (HATS) and

Associated Components Use of DSLA Equaliser to compensate for response of

Artificial Mouth

Base Station

Emulator

AudioIN OUT

Acoustic Chamber

Equalised reference signal

(artificial mouth

complement)

Equalised file

Wide-band reference signal

on PC

1

3

2

4 Degraded file

5 Degraded file, for comparison with wide-band

reference

Connecting Cellular Handset

to Digital Speech Level

Analyser (DSLA)

Lead, 3.5mm plug to 3.5mm plug

Lead, RJ-22 plug to 3.5mm socket

Adaptor, 2.5mm plug to 3.5mm socket

Specific adaptor, providing 2.5mm jack socket for headset

CellularHandset

DSLA

Lead, 3.5mm plug to 3.5mm plug

Lead, RJ-22 plug to 3.5mm socket

Adaptor, 2.5mm plug to 3.5mm socket

CellularHandset

DSLA

A: Handset with proprietary hands-free connector

B: Handset with 2.5mm jack socket hands-free connector