digital speech level analyser the information you need about speech performance
TRANSCRIPT
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?
• 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
Digital Speech LevelAnalyser
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
Digital Speech LevelAnalyser
DSP
RAM D/A
A/D
A
“B”
VN
Using one Analogue Port and one VN
(IP) Network
Digital Speech LevelAnalyser
DSP
RAM D/A
A/D
“A”
“B”
VN
VNUsing two VN’s
Data (IP) Network
Digital Speech LevelAnalyser
DSP
RAM D/A
A/D
A
“B”
ISDN
Using one Analogue Port and one ISDN Port
Telephony Network
• What is the DSLA?
• Artificial Speech Test Stimulus – Phonytalk™
• Scripting
• Speech Quality Assessment
• 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
• What is the DSLA?
• Artificial Speech Test Stimulus – Phonytalk™
• Scripting
• Speech Quality Assessment
• 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
• What is the DSLA?
• Artificial Speech Test Stimulus – Phonytalk™
• Scripting
• Speech Quality Assessment
• 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
• What is the DSLA?
• Artificial Speech Test Stimulus – Phonytalk™
• Scripting
• Speech Quality Assessment
• 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
Other Common VoIP Problems
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
Other Common VoIP Problems
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
• What is the DSLA?
• Artificial Speech Test Stimulus – Phonytalk™
• Scripting
• Speech Quality Assessment
• 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
• What is the DSLA?
• Artificial Speech Test Stimulus – Phonytalk™
• Scripting
• Speech Quality Assessment
• 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