Digital Speech Level Analyser The information you need about speech performance.

Digital Speech LevelAnalyser

The informationyou need about speech performance

• What is the DSLA?

• Artificial Speech Test Stimulus – Phonytalk™

• Scripting

• Speech Quality Assessment

• Sample Results

• DSLA Users

• Support

What is the DSLA?

• A precision analogue instrument

• Purpose-designed (not a PC soundcard)

• 24-bit A-D & D-A

• Noise floor below -80dBm

• Better than 110dB dynamic range

• Advanced analysis software

• Digital connection add-ons for ISDN and VoIP

“The best quality platform available”

Analysis Software

• Voice measurement• Signal analysis• User task scripting• Task scheduling• Graphical output• Data logging• And much more…

Network


DSP

RAM D/A

A/D

A

B

Using DSLA Analogue Ports

Analysis of Speech Quality

in a Network

via Analogue PBX Ports

DSLA

FXS ports

Ethernet

DSLA

NetworkUnder Test PBX

• Speech Quality Score(s)• Mean, Max, Min Delay• Echo Level, TERL• Speech Level• Noise Level• etc.

DSLA temporarily replaces the telephone.

PC

DSLA Application:End to End Testing of Speech Performance via Handset or

Headset Ports

IP Network

DSLA

DSLA temporarily replaces the handset.

IPNetwork

Remote testing between two sites

AnotherNetwork

(IP) Network


DSP

RAM D/A

A/D

A

“B”

VN

Using one Analogue Port and one VN

(IP) Network


DSP

RAM D/A

A/D

“A”

“B”

VN

VNUsing two VN’s

Data (IP) Network


DSP

RAM D/A

A/D

A

“B”

ISDN

Using one Analogue Port and one ISDN Port

Telephony Network



• Scripting


• Sample Results

• DSLA Users

• Support

• Representative sounds and transitions between sounds from a conversational database

• Efficiency by elimination of redundancy

• Spectral and temporal properties are speechlike

Artificial Speech Test Stimulus

• A linguistically motivated artificial speech test

signal in different languages

American EnglishFemale Male

British English Female Male



• Scripting


• Sample Results

• DSLA Users

• Support

Using speech signals, measure in real-time:

• delay

• echo level, TERL

• noise

A Scheduler automates complex test routines ….

• Avoids tediousmanual repetition

• Permits unattendedoperation

• facilitates remotetesting

…. and gives you full control

• Either one or two playlistsand the channel settings

• When execution takes place

Each task defines:

• How many times



• Scripting


• Sample Results

• DSLA Users

• Support

• Measure, repeatably, the mean active speech level - ITU Recommendation P.56 Method B

Test duration

True RMS average levelover test duration

Mean activespeech level

Percentage of timemean active speechlevel is exceeded,

i.e. speech is present

Selected unitsInput signal source

Instantaneous peaksignal level

Noise measuredin silent intervals

What call quality do you get before and after

voice/data integration?

Why not ask the users…?

“It sounds a bit distorted”

“There’s this sort of warbling

sound”

“… sounds alright to me”

“It was OK last week, but this week it’s been

terrible”

“It sounds awful”

“I can hear my own voice echoing”

“Well, it’s better than

GSM”

“All that money and it’s worse than before”

“You wait ages for the call to go through”

“What’s that buzzing noise?”

“There’s more delay before you hear the

reply”

“I’m sure it used to be clearer”

“Sometimes there are bits

missing”

0.03

0.1

0.08

0

0.02

0.04

0.06

0.08

0.1

0.12

59.7

67

82

50

55

60

65

70

75

80

85

Comparison of IP phone performance

4.21

3.753.78

1

1.5

2

2.5

3

3.5

4

4.5

5

56.4

74.6

66.9

50

55

60

65

70

75

80

85

Brand A G.711

Brand B G.711

Brand B G.729

Mean PESQ-LQ score Mean delay A-B (ms)

Mean delay B-A (ms)Stddev. of PESQ-LQ scores

• PAMS

• PSQM / PSQM+

• PESQ (ITU-T Recommendation P.862)

• PESQ LQO extension P.862.1

Speech Quality Assessment



• Scripting


• Sample Results

• DSLA Users

• Support

DSLA Speech Quality Display

MOS prediction

Reference surface – transmitted signal

Degraded surface – received signal

Error surface

Effects of Compression

G.711 64k bps

G.723 6k3 bps

G.729 8k bps

G.723 5k3 bps

Effect of Data Loading on LAN used for VoIP

LAN with no load. Speech quality

moderate

LAN with data load. Speech quality poor. Packet loss visible as

negative excursions in the error surface; loss

of synchronisation near end produces loud ‘squeak’ effect

Other Common VoIP Problems

The zoom view makes clear a 20ms packet loss which has not

been concealed. The loss occurs in the fourth utterance

This is a packet loss of 100ms duration. Again, there is no

concealment


Utterance marker #5 appears in a segment of active speech. This

indicates that jitter buffer re-sizing has

occurred

The utterance offset (delay) histogram

shows that the jitter buffer was increased in size by about 6ms


The 2-D view shows some disturbance at the beginning of the

second utterance

The corresponding utterance histogram

shows the jitter buffer has been re-sized in increments of 10ms, then a decrement of

20ms



• Scripting


• Sample Results

• DSLA Users

• Support

3COMAcoustic TechnologiesActerna Zurich AGAdvanced Fiber Communications

Advanced TelCom GroupAgere Systems

Airbiquity IncAlcatel

Alcatel BellAmbit Microsystems Corp

Ameritec Corporation

Analog DevicesAOLArkon Technologies

Arthur Andersen

Askey InternationalAstrium

AT & T

AtlinksATMEL

AudioCodesAvayaAVMBarclays Global InvestorsBCM Computers

Belgacom

Bell Atlantic Mobile

BellSouth

Binatone

Birch Telecom

Broadcom

BT

Cable & WirelessCablevision

Cambridge Silicon RadioCarleton University

CCT Telecom

Centillium

Cetacean Networks

Cetecom

Cisco Systems

ClarityClarus Systems

Comdial

ComverseConcert Communications

Conexant

Consumer UnionCT LabsData Connection/MetaSwitchDataflow Systems

DBTEL International

Denso InternationalDFS (German Air Traffic Control)DilithiumDolphin Telecommunications

Doro AudiolineDynamicsoft

EADS Defence & Security Networks Efficient Networks

EricssoneStaraFinnish Air Force

FirstMark Communications

France Telecom

G3 NovaGeneral Bandwidth

General Instrument

GL CommunicationsGlobal China Technology

Global Crossing

Global OneGoldman Sachs

GTE Internetworking

Honeywell

Hughes Network Systems

ICF ConsultingIDTInnoMediaIntel Corporation

IntelsatIP AxessIridiumITOITSIxiaJetstreamKTLKingston inbusinessLatitude CommunicationsLegerityLernout & HauspieLevel 3

LSI Logic CorporationLucent TechnologiesMacronixMarconiMatra NortelMédiatrixMentor GraphicsMilgo SolutionsMindspeed TechnologiesMinistry of the Interior, FranceMinistry of Defence, UKMitelMotorolaNational Air Traffic Services Net2PhoneNetergyNetwork Equipment TechnologiesNext Level CommunicationsNexus TelecomNMS CommunicationsNokiaNortel NetworksOctasic IncOnStarOpuswavePanasonicPlantronicsPolycomPrairieComRacalRockwell CollinsRSISagemSalixSentitoSepuraSiemensSimoco EuropeSmiths IndustriesSouth West Research InstSprintSun CorpSwisscomSymbol TechnologiesT-Mobile (UK)Team ConceptsTecom

Speech Performance

Measurement System Users

Telesync, IncTellabsTelmaxTelogyTelspecTelstraTelus MobilityTexas InstrumentsThales GroupThe Mitre CorporporationThomson Multi Media IncTollbridge NetworksUniversity of GhentUniversity of OttawaU.S. Department of DefenceU.S. Department of StateUTStarcomVerizonVirataVocalDataVodafoneVodTelVTech CommunicationsWorldwide Data Systems



• Scripting


• Sample Results

• DSLA Users

• Support

Digital Speech Level Analyser

Technical Support – Free of charge, without time limit, by email or telephone

Software Updates – Free of charge, no need for contract, without time limit

Malden Electronics holds ISO 9000: 2000 certification

Digital Speech Level Analyser The information you need about speech performance.

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Transcript of Digital Speech Level Analyser The information you need about speech performance.