BSTJ 50: 8. October 1971: A Laboratory System for Measuring Loudness Loss of Telephone Connections. (Sullivan, J.L.)

35.8 MB·English

A Laboratory System for Measuring
Tamdness Loss of Telephone Connections

By J. L SULLIVAN

(econ rion Angst 8, 150)

‘Trasnniaion performance of te elae masage nator has én
prolly over th gone. Covnedotal th tae snprvanent has
dew the lation of rating plana whch provide he basis for ramen
‘axing, design, ae erlaaton Less of eptone speech ae ah
Ionprtatcoiertion vn this vn,

‘alepone speck fines contones fb oe ofthe major fore which
sent 1 be tab tao ecco it teptoe reson ngiaeie. Ta
Tr ier a taorony stn, lod BARS (Elect Acnate Hating
Byun, ao to mate ajeie mesuremerte of pata ard overall
"al nent iin ltreacoatie masa ei a
Taare which gta subst onsets. Topenontrd tae @
Naor eaine of ong plone, computa oath ovina, sion
Ofte BARS, ont ecrpton of ie syne a i pas,

The EARS emertalycnmrivnsund ure ud mal fr wi
wing eider semua prsnure a aecteat ate Designo} te tures
tout eer re fered ow llephne pch fess constrains, and
Imessuremets wae wth the sytem wpprueinate eject laos:
Jomnta wom ooaracy hich naont Jor tdephonaengivaring
The BARS may be wl in tnpleenting aay iephone tranmsien
rating plas icorparatng spich Loess Toss a8 a lament. I uth
‘ann, the apt cs Be on fr ape eons te, hua
‘tinting the sand for stereos tatoos Hoo,
‘adhesives be ryt want aet of ther lene,
‘ier any hen pn, a et te age fT
sr ns explo hp

‘A basi ell Spates objections prove ir customers with the
beet posible telephone mwssige Urisemission onrsent wih the
24 ram am svrmw mre SOCIAL, UC

stuce of the art and the coomomie clizatto—has reruns exentally
Sunchangesiuce the easly aye of tekphony, Lowever, continuing
review ofthe tlophona system in tems of ths objective fs rule)
in steady inmprovement in transmieton performawnes of the aie
ver che yest. Such inzprovement hae been made pessble By erowsh
in our toeanical sie’ it aut been mide neciswury by evolving
testoner seeds Jor iniprose! transi Teed, bes heen por=
Jeted thas a our esters ive the Uephove, thes” beenne 96-
fusconad to wuren: perfomianes on come to expest felaor ite
pnvemene*

What da we wets ly telephone neseage tsurainin performance?
4a the broadest went, Lie refers bie eel ofthe syste on mesh,
flguale when trae signala ate Ursninitted over telepone oonnestionr.
Customess conversing ove telefin eonneelions Want 0 heat Peso
bly ilu, wodistertd reproduevions of euch others woives wil
minimum of effet Connon far which Bose randitions perikia
an be thought of as proving satisfactory transmission perormsnee
CConnesiane exhibiting serene csostion woul thus neoeile sine
sting wee (aan aaistcctary seeforance; wtonene sight be abe to
feamerae bat aly with exetene daly

Sieech leenanissior: eapabilire of he telephone nctwork are afte
considered in seme of individual transmission pasatceter, the eot-
ination of arhish dceraines cove unsaisson pentirmants, Sete
Bf the rove impoeian’ parkmcler are Toe, ample distort, md
Tuavated interfeenoce sh as ise, erste, and ecko, Improve:
rent performunes ver the yours has been sehieved by design to
fentzol these paramcters, singly and in combination, es dictated by
Me izetnolags, exami nnd outs of te Gn

(Coineiental with thie insprewement. jn teansmision nerlormance

Ties en the weplubion nf Ieeponr lsmission ing. The problem
sf rating, aw eraluston and msanarenert hee Inet the ie
fowveh thougeh end snc ever many ports, an @ numberof diferer:

rly plane evolse lo meck the lramenission design nea Tor ne
Jmproving and exounding tolophone sacssage ocbverk

For pretext purposes, © transmission valiag pl. comprises (7) 9
sting eitarion ‘whish represents the basi for ratig telephone eon-
seein, [i] a ference syatem (my he physiea!siaation of an
vera slephone oneetion, a se uf deletions, or bolh) wilh ome
fljuminle fontie in terme of which comsettion ratings ate esta
Tish esd on the seer evieron, ond Fill rating sale whieh
is eeecutnly represented iy Un vacvble Teslure of the referee
Leen acuuse watts Yarn 2605,

system, Thur, a rating lan provides w framework for Lae design and
evaluation of selepuone eauneetio=s

istoviely, the satin eritvion was eb)
eonive abotine ting ar eguived to evaluaze telapone eounee
tione in taste of Uae selecenee, Moreover, application of sbe wasioue
rating plane zequird subject testing to evo te sere eas, 2
Teer ye shal vale vee (and eceneedione repmesit? aay wl
perfore:nnee

‘Trarsnission weroemcaee of the clephone message ntverk bes
Improved tot pot hat lols lye ea zajoe vannble whi oe
for be taken ino cotunk i bovis pleming kis paper de-
tevibes& laborer rating vale, mld the FATS (tae decueie
ating, System), when esa 52 ute w usjeeUive smears Tans
Jove of teeshoe eomeelins x mehner wai elesely appmoxiuntee
vbjeetive Iozanesssudeanent, Thus the eye supa aijeenve
teste wish would exdinasityb wx el eecovmine Townes ating
Ct ronnmstirs, Momeven, zesty will ill bo rene ol a entering
Fbjective searcen to Sanois arwile of llores, aul so ees
tine astageistonshi besten ule ge and acer eranemssion
piereneoesSoiprtant in any given reing ple

"The FARS wn ss‘ tn trees acmtin pessuene an loca
collage ee esined by loudness noting defaitions for oagtnl and
sworn” selepzone cennersiane® The MAIS Las Ino mst tensed
Cvor the ash sever ears to sheneatzie che louder pela
fof Ieleere sts ail emngchons, atl to evaluace desi ane si
Es unipnnge design af te sseaer lop pl? Viewer, “nnes
lave ne sesinel with the FAR is gx atorlant clove a ute
ilies of -xeainsion prasning oased en w rubiparameser anptoae
‘novia her transissan fuetors, eg , mrss ar oho, wee ‘ated

linss Ines lst, the FARS sonerst fs ono? severa) ali=

Altes fer acopton cv senda thon of specifying losses Tos

‘The EARS cevcnially cout: a tnd source wie is sel 6
cnergie tie talking eve uf x tolephnyw eannerion ant an inewsng

Ime abil is used tg nous your ie jute oF Hoetzial weltage,
nl provides ¢ simo/s roms af macasting Spur sad eutpee sigzal
levels for pata) sor vera t Ieleptinee cnmrtions, Toudess lesces

oie Sk es Syne "i cit nite ect em
preter ae aie) eeu “egies Beat oR
B55) TE RELL sveTaN mREERENL SOLAN, HME at

of commotion: and enneotin component, ineuiny elzelzo-scoustie
traneducers 12, telephone nami. sci? reeivera, are then the
Aifeenersherers Sap ar enopat signal eves expressed is UB-Hke
terme relative to anproprite rence signal levels.

Tie epprusel folesel iv lv ger fet sans the aistny
of toramaosion rating place aa, steam, tn seuss the esatution of
the HARS. Discussion of rating oluns in Seton TT emonsrates the
interelitionshps 0! nab pany win natin, an nerwone ene
triton performace iiprovenents, Covslacing tenets entine the
teietion bstreen ladnese cusng define so ie ring Fates,
the EARS, which teed la delernins paraates vie ap muted
buy the rating cefnitions, Also miciGe are mieten snow cre
reneed with multiparameter netwock design and evulsasior

Diseusior of the evolution of the BARN invo-va several steps, We
toegin in etion MIL hy aot quneees tw a evi of vexious
toxin for eumiting the Tolan af anes, lie, ate epee, chen
Alizeuse ia etme deal the dervation of @ parielar speech Toudnes:
fonnpitation wlll, This sisson frdiates tae manner in whil
Freuueney roskins eitsceriatien uf etal ant avere camncedons
faa be measures and shows how from the meseured responce for 8
ven eouzsdtion, 8 ean gorse 4 nutine whieh wr ile? Lond
hess. Alin ireluced ie a comparison of coxputed and evperinertal
tis

rion TY aovies éorvadon of the EARS fron “he speach loudness
roenpuaie> nin? enferevalve and deserves che EARS i ite
freer Ear” Als lear ia gespiealcoxpuretien meshed based
fon the isin cenvepes icing to the EARS

Tu Brciow ¥, ae disci the arcuracy of tas KATES in precieting
ubjective tes, fells vl wider Fv era o® amplifying aeearape
tions employed in doriving the ATI. Tae weblele for tala is tae
(mapea! meted referred to abuses, Ioal’e enmpsiod sing this
‘ethod axe compaced to observed results er dhe esjetive tela ord
ii vaudatng tae epeseh loudaaee compsntor reehal, Thie proach
ia neosseazy snes abe subjective ts: system are 9 longer acl,
ard hence rll noe he ensured direct sine (we BANS, Tuerefoe,
tls coupariaea of ecrsputes and observed rect reforss eer
fof the comeepes oa which the LALGS i tna, sd uf he FARS
itl

fs will bowie ooideus, the BARS in ate posses four is only ont
of sevenil wine in whiel ie eunyntotinaal metho raul i mpl
rested se leboratory acura essen, nd = nl an exe rene
suavane-acut ome mar eT na

tion of the empl ythod. Thi Zorm was aeeeted becuse i
Divides a satefeetory corcinat un 6° spe mp pment amerar
fun svt stele cabana eaten. pws?

Tistosonlty, tansmisien eating plane depoanat ot sla ise of
referoie cieeits sh whieh eomzerial res cot dy vou-parad
fxd 1 syatenas of ele for expressing the erative eaizgs thus
Alleronwl. A great le of eubyective testi ras nesesany to tex.
rine nat'aye of enmcricl eeephase equipments and city wl
te corelte Une rage silt vensunable tremscisser. rupert,
“These ratings, in terms of he aypreyrinle yatent nit foe expres
ig the, wae ured och ad ewalseion af he telephiee maseage
veto.

(Considerable mors wy as anor be determine ‘sanemicson
sijestiver ir hae eos," i, the ecesee noel sal solace
tants previded the meant of exsesevng invewnsson pernemanee! i
tris ther cuesnry br sleerning the rating, oF Tenge of ratings, 4
ie the alana aul be desir

1 renamitaion Bguialnt Mm

For ¢ ins following the wen ol the eur, eepbose eeesite in
sonmsernial tHe hea quite similar clucneloiaen wel sardine mers
as tha seamtally only Ioevees, volo, eaahliny xs under
“oma of Te eanganiesion engineer, Th portray of tenia wet
Ateseraiued by comparing Pet, ot 2 -oacness bass, with « refer
fireat tick wre ad'stuble a allemustion, bat wrese other rans
diasion ehielorisine wen 1ypical oF eexmersia sieuis

“The zeerence Gel ir wot al Lata wae Kon as che Scanned
Cdhle Reference Sreiru (SCTSI"" Th emwieted of tlopene ects
finehedimeseanenters asd enerens ond eens (or eapsly mg Ue
tegptie et cariuc Foeanitinn with operacing surgent), eam
Aijostable ariel Tis Jor ite-rom esing the ord cenit, Those
Fenelon eenpanenas were rpnesta:iee of pee then UEe com
morale

‘The ling of ekyiuons wets 9° somaring tas y Uwe refennee
cionuit ivotved a tlker spe alleustely ae tke cst eeu: wl
he velecerenemeuit,alw Fev ling anny =the roveving,
tae "The tference evi lal ine, elbasta i, terms of =
Drstandard cake” ss nljted wai be hetener ted she valine
2968 em ams, sverm orem, sOTyHt, OeTOHR EMT

or Loudnese ofthe tb source sepsonate. by the ta ein tbe
yal, ‘The Zumber of miles of areal lie in Ue rolenmnoe «eat
‘ria ther oeel es the “transition equivalent” 0! the dian anor
veai The eft af exy cheage in a tee: exert on the edfeney ef
thot cine coule than oe mencuned by aacerdning Ue "irwmnssin
‘sqnive'rat” borane av aftr the charge: che nurber of zie a
tei Tine reine! i rieupwaeate tne the change a8 sed an an
inde ef shi effect

erlosmaiee iingy asigned ie terme uf le af sci outa
loudness based on t3> comparison proceture astlized wove eau
luted « pvcstechle gun efltsive ste of aneeong renemecion per
fomusnes, he saver lfc uf silore sure manor on
tensive quality vere reeogael, ba, te stoy war keen ul
ineonperating them, eoscther with Ioodnese Joes, io w single fie
At meri for rakiag cramsumeion pienmance® Monae, OMe =
TavityIetaoem rhe aecorann siult ane soramezelal eireuite ue tht

Tine cure ih inseptaien rn rosa

Ne the str ef the tehyhare e-velnpe, monday che
elutes cin’. tuowne desea 1 water ‘ot He ive't Fae
fetisinetory fl, ite psrpote, The oalaes Ting Ine onli
ations wore (2) amperes despa af trleyone ateuconte al cit
fuite, (improved ewoavi Techs ead rt aed 83
ke rex! for bore aizable til aa the are wf snare rable!

he atlct of improved design anus ve inttine into che plank
cleshone sustruscente and eins sti Ine ese evaeion Uo
ornsjmoling care af Ihe Slavcerd Cable Hezesenee Syste, Mer

(Gig rear F Tevanc saxty in ve a ee eee Yate
Tiel tnveaiaion wee™ he rsh pans clepene Re oF ave
cee Tess perfec, ow he aed il

‘Secon, the perfomance of Hie Shamlan! Cable Reeouce Syste
wns spo asa: Kine of apparatus end ereiteuese. Tae
eokson nin tty nyse il chee! Mp lage, exe
fund fupeance meawrcnns, Hawover, for lhe Lasalle ad
evivers, relia far nmslsnry of pestoriounr wa lane peneniye
upon the earefl ieatenance wd request eros consis (sub-
jortve} cht gemup of omananistet and noncorae which rete pect
Constreted co ince some of the sono of waration in she regular
Ivicel intruvantes” Tnnpeneuronte fn execusing ceekniqons ad
Frou le" se I eco erty erleiioe
of cesne-aemietir treraduers The i tar pemtentssletion and
fruininaroes of traveiores tv awe Tnng term sce.
uncrmyeseus ease tsi Senn nae

nally, « ekenge in etirg wis ter sails foe 5m eesons
im, sovuiln wer Rsing designed rich "ad lee dcceton Uw the
sical able of lle Bancend Cahie Hofoeesee Systems, Sinte tile
eae with this s¥stern earespavdcé not ony 20 a ceria voluie
Fnnge, ft len ta a iistorace cage eineneeroing new eteite

in seme of ales of eancenl vale inti! a igention degradation
fol wsvseayly acenbutale io the seu inler ues Broondls, be
Wlifewne erfonenan apezete wens rt men te i tho Te
Salm, te ahve ia sere ether chantvoe!" These syslorme ae
alfa ete ith siteont characcerivise, That wed Kew Tht
States hed a Tons tesstance o: SE chane ains a eon utero O16

ricer pe mile, re atte ned areal eae having le sate

resistance ed eee Il he i sfetion, an Hnuctance af 1
tnllibenry a a eaasuotane of 1 eeremho por mile, Tue, 2 cr
Creve somal with oaoh of hese reenensee stoi have lo Ate

ferent rai assign Lil The fist of the above zeazons suzsested,
the need for detortinleee wei, uy eral lat 8 ermoe wi

"A ce sty tale the Tasestneson Unt (TU). tus devises by
Ue Mer Seat!" This mse a desoetorese,Ingastl mie it 0
then a 20 ote se nT emia logerishas cence: i iran
fies ermgnrations, es auc wa ery neon the exe othe ost
of a mnie nf samncenl rae ao, ete, existing experience Wace
ferme of ulite of susuaed rabie eile be fiver le uw ea
“olan wits ¢ matic of Aiinlly. The Wemnemeson Unit Inne
Tpcatca the daubel 1"

"The thees factors Whcussie! “+ piecing pazagesphe ree" in
‘isin af the MeetcrLte-ersne Systn 1 RSI 8 Tha eystam atkoed
tranecicers WU, vor hn is wrion, eof to compensie for LEO

rio efeney of Lease Cares ae senpared 29 eammsreal
firnneni, al An areal Ea eonseiny eel 62 a 6O0-chma
Srtouuntorh “or anessouresting the ‘earring, nd roving le
tom's The epstens swe pmivsier for asecting Uist ng ete

pw Trova soe soevingelemete 90 that pexformetee oF

Seer te vacate tees oe att? saci ae Sat
bab mT oe are be Bg
Be eerie ne ae
Hats Saupe ic eee ee
SUN OTe lan eb Seteedll i 2a Sa
210 ra seus sasrame aecasuunL suuees, Goro TF

commercial trensdaene,charaoteriged by smpliade respons murves
‘sith pono seemans, el be ante,

"Tranemieson exinoeting wre ail Gone on a Zouceas basis, anc
Ue MIS wus used Uy busi linge in Lie sane mann as that
previounly deseriaed for fan SCRS, ‘Thar ia) speukers ‘lke
altemetely aver she rere ut leona, ahaarsers Hitoned
fer the eysceme, emvteing wif the telket, € 2) be line (000
fhe stteneator! of the ELS alee to ohca’n egal Ideas,
he average setsng of the actemintor 1 @R wise ee wae ten
le alg ofthe eyecea wader test

dep: of the MRS by tho Hel. ymonn hat inp ong cma,
fnte on ineematiasal standaeliztion of Weplaree relemce ae
Tome Ta 1895, ‘he CCT invites sepereenowaves of dhe Bel Sym
va zie with a cotnstne appaince hy tae CCE to eazsidor caption
Gh a crumnssvon rforen sfsonn 2 the weotsinendstion of hit
Committee the CCT adopts! the WTA ‘ev nf thee eseentn mee
rll abe Usk Sesteu, One wae eetnined at Ball Teepbase Lab-
craveries in, NewYork, lve oll on sem to the Tshoratary of she
(GGT in Paris fs 1928, The CCT Selon we serge! the SEHR

In che lato 1960s, the STLIET wns reyacel By a new refezence
spite, the NOSHER ? Lhe NUSEIC iy vores asl earl
That is egectialyequiveler: ta te STERT. Teleshone vonetion
wings cbc] sith rher the SKERY ot the NOSFER ene doi
ated ne Tolvevaen Tapvaleste (RE) in oB, and exe sumericely
equal to ste wily Gi Bn the wsoneaee systema line actomsatar
euired for Hnden Tae

123 Bfeotve Ines Pian
Tn the carly Ite, the Bell Syste contd = new truneston
plan, The ehangsIreamo neversary bers of telmologien] svc,
‘ueptone wa immnrorating anauetsee sieuitry ond inwoead
frenscoeene equa wy Ve ced ‘tal [tne Bel lem, These
fete bad poorer lenlrsow erfornance ‘han chr nears, fh

Se ee a tat Sere de aS
SE

CREEPER Tet mere Pengo P
ee Ry ae EL BLE BA
sarees aero namin serene en.

provide amrked snprovoneat 4 sels sharaeterstios a sitne,
frcplitnde dherontion, and net inet: ditesion, «ll &° which ave a
athe! effet a trtneninvin. Favaltabien of tare celephone sea in
ters of tho old system tended sn criphesne loudeess dieenoes at
the expense of these other factors, ue, thore wm ne for & mang
plea Raich peopesty rerogmzed the iuprovemeats gr ab the stane
tn, retinea appuieshiity for the older tlehone sek types "The
‘eeive loss lan was devieee to niet thie nea"

FRacings mee the new plan were in terms ef db of “lective” loss
to istingsish thems from "loudowne™ o= "lume Leste of the old
ben, Effective love represented «gure of sort for evalnting the
‘etivoness of the transmission aver telephone exeite sd, we such,
twas a mensure ofthe ability of (leo listeners to undatstand as
swell ae to heae traneitted tsiephone spoedh

"Eetiveeranemison nly were feiormine in terms of che Wek
ing Referens Syetera (WIS) "Thy aynte vse! of represent
tive eutomer Inape and tslplone seis and a variahle, istrtionlss
trunk, i, an attenuator, Hutings Tur cummeial eonnentions ene
cehvained in eet by eomsaring thes, using ve Lelkere und listener.
‘with tbe referezee sever, el ueing Ihe rtoetiontes tank ost che
reference syaten end tat senzseton vere jukged to provige equivelent
traneninfon, ‘Trai data fo the plan wire obtaines Era Uses

anversntion, ces, in eoabre tle water lar ior whieh ata
‘Sew ort istonmanly dees, The etevion for euch ecuality waa
repeiton rite hab n Piece uf stitniee of sepeisions aeqieted
by test sues To lnlvs wan aries whe che WRS (ith
{partic er tran: str) aul fs tse omeetinn provide te seme
epeston rate, Tie WQS ¢ronk selling, (4, ae then a mesaune

fo the ifectiveness of the cist uler tes The reference trunk
Selling for the Working Retence Syetem was solvted to provide
Thumneriea) oquvalncy of ratings obtained wih the new plan end sts
Droeceor With mloreacr truuke s#tting. the Working Reference
Soto hed nn effective lee of 18 UB whieh was aleo its transmission
feqvatent hte ofthe ean plan,

Daring the early 19806 wiv the este lose plan wes ander
evelopment, in-plinfeeihone vel esunducene were predominently
fof the meonstl ype, eburarerivea Ip lange amounts of amplitude
land nonlinear distortion, teleslane see ware Tage af the sides
“areiy, and a namber of lew euto® able Leading systems were in
tite, However. improved tracert aril aniaidelone sul were being
Intros ‘nfo the plant, and additional itaprovemonts were under
2072 TG mL ose TUNA JULESAL, OCHUDED Is

Alevelpment, (The trunsional nature ef che telephone set plant
ft tha? Game and wldivnal gnrod inprosemeate wene important
fomsiderations Ieding to adoption of the elective less plan! This
reste in intsucion of tho 8OD-sye telephone cet into ti pleat
i 1037." Subsequent stucy simsariy resulted i atrudueton 0 the
00.1ype telephone set inxo plant in 18502% The efesive loee lun
encourage thew improvementa and, aleo, the adoption of higher
‘utofetble landing set

Hy the mid 1080, tleiione sided suliient antisite
snd freedom from amplitule and nonlinear distortion that ite would
bre joined iy Turiee inpnvveateste, Ths, loudness appcared to. be
nee again a major variable factor in plan. deign, likely vo be the
‘host important eovsideration in subsecien:velephone et destin.

"The wn'formly high level wf teoatiasion pettormance sherectera-
ing the plant suggested vision of telephone teenamisson planning
tu rafet stare emphasis of ladies eles. Tmpenas far sue 2ovision
vwas provided by (?) Ure availebility of speet louloees enmpntation
teesnighe anda shorntary ensuring peter based oF this tecigue
snd (8) the need Zor plenniug in simp.or were thax was poss ble
With tse enti Ise plan eh sent foom « osmber of peuetical
Senate

128 Lenwness Ring Phan!

For pisiere porpoe, che lowdae eating psa comptes éefnitions
for tiudiess ratings of paviel ane oveeal. eepbone esnortone”
Loudness is ¢ subjective quantity anc, tharsfore, loudness rating is
Aefget ae he rato the laulrass af che apwesh fea the Tener’
far tothe loess of Cie speech wal af Use take's mut. Aa ee
hee, however, loudnece rabug is considered w be determined by
objertive meseuremests

‘The rating feSisions involve hath asoustic pressures and lel
vollages The RARS peuvides « meane of motsuring theso quantities,
"The EARS consiste of a sour of aeoutie energy, eotaprisng ¥en
plex voioefemurney test tone whieh simulates ert nropertis of
Finnan speech and a entifieial mouth, and an indicating mator for
‘mousing voltage or aound prsceure ip ¢ manner whieh cimulecee
the louloesspeteention of an average stner.

Ratings obtained using the EARS do aot p

iy equal ratings

Tefradeet, ring ns acd Uy the tains are expel i deat
see Dee eset ely seh a ea Cr ae,