BSTJ 50: 4. April 1971: Statistical Techniques for Talker Identification. (Bricker, P.D.; Gnanadesikan, R.; Mathews, M.V.; Pruzansky, Miss S.; Tukey, P.A.; Wachter, K.W.; Warner, J.L.)

12.7 MB·English

Statistical ‘Techniques for
Talker Identification

My B,D. BUCKEA, K CNANADTSTEAN, M. ¥. MATHEWS,
MISH 8. PRUZANDRY. P. 4. TUKEY, &. W. WACHTER
aad J. To WARNER

(Gtancaigtreirad Movember 6 50)

his per proien ae anerview of work on state! formulas
‘ra aman aorta th the prablana wwe fping persue on he
Inns af spretrat energy Tenesontatcns af asowstica eitsree®, The
intetiotion ase tase soypvieal and the oper fecuace othe
Getistea!teckniynen mul lone tak fe eon devnloped im Ee
ontect af analyzing ter senchin boiiee oj date. The grobiews and
procedures t9 be ecwcerd sactote: (3) dy erulemacton wad Fore
eatutice; 01) eont and preticalertria for elossifeasion aed ite
Criminativns und 3) abvatagie fv tonne dentipecton of tlbath
fn relaty ay Urge papules

‘Mens of ms enn perhaps ser! the axpsiene of identifying a ent
fo the texphowe (rva a rn iurly ahrt tteranee meh as the word
"ital." Tie mths iene Cha even stork ullerancesconrain eu
cient tnforation for dent Seatn, ne iho ine ad intent
Ing problem to inquire sehr wld, wjetion setae and coe
sie methods eat, be develeoed for (ler rrvgitign, Toe aulbate
OF et lent rm papers i he I gh Sas have ynorted experiments
SSE (Soulate wats natie ake rerogh acre Using a raciety of ap
Drowees to iferenk gap ul ee prt, dase enpesineniee base
fot mith stokingly Gril snows 9 peo farsave) earoae Dee
pation

Previous studies way he easitnd fata seo romps aosocding to
bother she proldeeswcrvered wa tarifeutin (i ie spealiee Whe be
Clans a te ionsfndion {assim an arkcown tteranee
{one sean in piven group of speakers. While to scien of the
Figs aia involved 84 voices oe Kos? the Wind? ad uaaet evans
14 non am, svetear mmcenaenL soLagG, ATT

(108 voinn waa muse sueesstal,welfering an everage af 9B porent
comeat. or femtone. Four studies of Cie sevrcl apse used qui dl
Teroo! buses for slonitecliny mex 0-3U vuices) popes
‘uring ftoo: sycele] aalyses of Enard gover oe whale word wo
smuapurntons of posdegion eatszee Wheres al the alu studies
regained te salem U9 slvr ptrectbee text chrce olhom hase
fshiovod drom 90 ta IW oecnen: some: nse Livy wilh ms sm
rersines on wha the spenkor wis provided that ¢eaffeleut quality
bf epeech from cach talker i wr! te, Again he procedaver employed,
tv hone Tas iy tues havo rfenen widely: apoetral analysee ©
tae speveh? of! recs uly? wee narvena essoen ere points
in varios Srequraey bunds" wer wel wth hier dilanen2eeogntion
schon,

"These rele with smal popubione sgn that the apeceh sigcal
coving a enh infrazaion about te taller ak ca be cate
ised frown among Dov a by a vasizy of prosaure, and Cat we
‘sev Tenn Fron thet ence relsivw ner uf wars WR of
Fepmecalig ‘he aigna) and teaeking a deeiaon, The wily auc of Uieee
studios Unt won x hunceed ar mote voles? requized only thi eae
sunkovsn hs asianed tn one af to eeape {genuste oF i:poeor]; Het
Jouve boc no bul of dutifieaton i large sopalions, ‘The omer
dtgeilus the evelu ‘on of wrk adnesed tn both th eral end sige
epulstion sonication peoblenas hy @ group of peu, ineheye the
Drteent aullirg, over the Tash few yrane. Aside Sem che pe
fusbors, ule why is sail in eiterent Eoeta of thie worl
fre: Mra MT, Rsk, Mis, T. P. Hughes, T, L. DeGasine, B.S
Pinkham ae MB, Wie

“The work co be dorlné bere esulvel empvieliy end exper
taentaliy inthe ont of analyz ta hodies of daca. With no gen-
fre theory being available on nih digi a Donen Sor tees
Sdenigeation, thie wor ved hewyy san anaes of data nt ly
te guncant ens id trhnicc of poreible reletsane is £10 9 ae

the personmance uf aay el-vme ‘Tea Ue prnyaatineite i af oe
served propertions of err rerglin i Usp eg Taine alee
Utiined ge the roocherone rather fhan amy goseal Theneical epic
tasliy properties,‘ al wale urea i hse pena

to be practical nod produstive, nad mest of che exeuss‘u ier ad
azcthose ate icy abvione—eapciniy aster ho foot

‘The presetation of tie data un yeis wad deekion processes may be
sere in four parte: 6) The data-—the twa bodes of cata stihes Fi
Le deserted, the basic digit) onmet ef an aeoustca! utlrnace ill
‘raLaun oxsnisosnee 9

be ceecrba and deploy, se Festuces ofthe data wil
Ie dienes. (2) Dato condensation’ several primitive procedures
wll anacoued fr deriving anna limensional representa
‘Hoos sera the original iste (0! efi of « space and metrics,

the umnnsa, and the vesious ewdidates for wssgning 1 bo, may be
‘epreseuted a the space ofthe surimury eat, se several meee may
a spevifed for measnsing “he stance between the unkown an the
cavdidates for sdeotieatin, 128) Ciaesifonton amen ond aratniee
for identigention—c, prneeducee Zor uaigping ex unkoowa ins
reltivelystnet popilaie contending epeakers a well ms statstie
fat stelogirs far elatin i sltively ange papalations of speakers

“The evo bots of eat involv in ne sly bath ea with repented
snteranee of single words, The fe elo dita (el. 8. Prazayaky® for
see desertion} is fen on cakes eh of whom yielded several
epctitione of ten wore commonly need i telephone conversions
‘The sctual weteranoes wen exeorie om sesteneas in sich the
won wore erbwcded aod te tele, fz fe, red the ne ees Por
“noe ialker-med combica:ios shore ware eoven reliolions with om
Stow rine 1698 utterances were aval sea of 700 = 10 >
mt)

‘Phe soeand soy of dts, Which was clleted subsequent co pramis-
sng seu obtene withthe fist «2 of dete, deale wih s populesion
fo 172 speakers cach af whom repeated rar af dive digit name (one,
Ihe, thoes, foe atl we) five tines. The wonts Were uttered in ola
tion rather than being embricied in sealenes, ‘The send body of
Tia involved many more spenses fewer wants ad emer replications
‘lative bo Ue fst act of data

‘Whereas te fir oct uf recurs: was mae under eavefoly con
tvnieeeerditions fsee Re, 5, the sal set wee wade in an 1aat-
orl eet in a bey eazeouse,AIUhogh a h-quality meeophene
sensed, it-vaa housed in tlophone Tet, ll w sho (but vie
{Ae} sistas fom th igs Avteracieenaipmene controled «doles
jn Ge Bool which eved the talkore 280 hich digit name te sy and
‘hon Tw oth ens, all tcerasees by a given taller were oer in

nthe present report, the dieplavs and examples are drawn from
anayaee of both bes of i'n wl he pwoseataln wl suite hel
fd fora beucen the two sets of eas
149 ra amy svSIME eMe-MECAL SOLE, APA IL

‘he most for of Uta ie jut the ui rewrings. However
fo rapases of anal, th aio trooednas were fe nko an anslos
Flier im si fae Alter outputs wene aunpled wt fo, request ine
rals of time (Kmilinecon intervale in the fet boly of dats and
Grniicwnnt ingervle fa the soon set}. In the fst aeh of si, the
flute inom 17 fonteneyehaanele covering a range of 100 t9 7000 Hz
Ivers fluined; the at 16 shunnols wore ayproxitacely equally spared
long s Korg eonle vrs 200 ta 4000 He, while the Mth eovered ie
Tame $000 to 7000 Hx Tbe etenad se of dts she oul pate soa 2
Trrenoney charels shanoing the range 20 to 20H Te weve seesined
de upper etd lower etzed ieee of rac af the 20 Ale=a a
‘Rows ov the abvciea af Hig. 8 Enel wucio weraboe ‘apa: thie
‘Psided a certain sumser (17 we Uw Tet set of data snd 20 in the
econ) of svete sane series ae utp, with each serge representing
the energy in spore Tequenay bund ns it varies sevues tine. Tox
Gather the sores represent che srl -nvespetram ofthe utterance

‘Thm the hasie digital fra of Ue dal for an lteranee onsite of
routs of spelen] eergna ees’ overding to Fequeney aude 30
Gach of @ sequence 0” Hine ierle, (sop Prova & Matewss for
fs ceserpion w! energy Srequeney-tine quvnlieaion-) Tale Ti an
Geample of data ates onmn the seeard et of data, Ore van aban
pintnsic.zepresen:ions of sak ¢santris, The cee wyesontetion i
fhe soar spre nage, whieh © undortanctely vot san for eas
read by commuters Figure 1 eaowe a eontour plot of lox energy a2 3
Finetion of time an feauance; i wae ebnel wea compos prin
foom a date mali. Atthong® dexived in ¢ stcughtforacd wry ‘rom
fomputer-eale ala, tie pl eonveys some of the visu) sepecle
tf the sound spcotrogea.

‘Some ramen an vortsin sepets of the data are in onfer= (The
teal volume of dts ir large.) ‘The basie disitel representation of

‘Tanta I-Deta Maumute von an Cirrmnanon

a Bok of 8 8 8

1432 rue atu, aysrmae TeomuEML soussAt, APM, 1

‘he dasa foram atzerane i intraethiy high in dicensirulity for per
forming ettiaten) wnalyen. [For tho fret st of al the metriers we
17 x 60 ‘appro, of #-diensions, per suteranc; forthe second
they sere 20%. 273 ype), oF S8N0-densional, per wlteraree!)
fii) The geceral level ef the energies way shaft from l{erance to
idlerance of even tae vem sperker du to araiuetul rensons. (Lowe
reve may very for example eau 6” verging preximity Co he miexo-
phone tn) These xno atc owe origin foe tae daca an i spece
ication is arbitrary in that wa is Inlet aot 1 does nob
Alpers on the neta? comnmeneenaet of the wierance; this implies
Tack of alignment af the data for diTernt wlerences of a given word
coven by the snae speaker.

‘The conjunction nf the aloe four inase conveys ceri implies
tows forthe wren analyses, Fat, its essential, even for explora
tory investigations, to pa allelion Lo practicality ard effsioney in
coupiter procosares Seeand, iti eras! to find effete lower
rmentional represrtations nf hs daca using methods of striata
that wl be of gneral tility ols foe HPerext persera end for df=
ferent verde. Finely, adjnerk mart be provide for azeesetaal =
feets, cioh as energy-lovel variation and arbitrariness of the tine
srgin, Sues adjustments may be nevonpiche ther hy seating tee
Aint poe auchyae ox by wong aati! procednree wie make
prerisione for tke areessl ele. Thus, “oF example, exergyovel
Yaciation can be handles! cicher br moralivng [ evexpim wo Uhe>
Ice sum is unity for ech nttrsuen oe hy wig clasiestion pro-
ferns aie allow for lovl shangrs amoryet te repligsted ata
finees of specker let. H. Gass & MB. Wile). Biilaly,
the wbitrarines of tise crigin many be handled either hy peeling
the utternteee by rere eerioa, suchas The one vant hy Paasneky
swith the fet body of dat, or by usin orgin-nvarient time inform
Gon in ister anslyses

‘the high dimcasionlity of the basie quantivalive rerérentstion af
fom uttrnieo (vie, she atric of spentesl energies) is not only
femapatationally unienble ae comely Aiiew'k Sot alo perhaps
lurneressary. One woule expe thnt the high physica! en stetisticed
‘enelaions atseng the energies shout ‘mply edhindaney. The limited
Dues of ropleations aveilsle wats sorcerer, pes 9 mater
eal eoaatssnt on aeahle dimensionality. Por ell shee reasons, eamne
‘oom onasimextiox 493

smarizaton i neorsssty, The en foe simauary statis wre gion
nd the eonsequenees important, Varlone ashen far eodesing the
fafurmetion in tens of mavagesbly:nwimension statistics were
studied

‘Table TE shows a lst of sor af he pes of inforinttionsurumerias
that are invessgaied

For laelante, Sumaciting vie £9 tin -usrziz meme
comsidor Me energies martaliged) salapsel anv the hme sule clone
‘itl wny Znquency breaiziowa. Sinfsny, ep ieney tana means
thatthe ensgice normalize act none overall tho time interval,
us elisansting the information nowt sime-rsiion of the speeuna
Looking a fenpueney soe implice the conscenstion of the meng”
otis in euch of the frequency chenaels, With ras uf hee
ways of lacking ee the data, sere alterate tthos ere feet
tated Tor surariing the information, Hop fastance in sb the
Fine margin both the energies themselves es wel as characterization
19 thei ltelition nore tre in terme of ett lon-oedes wont
fnvean, sane devidion, ee sere vestigated, The disttstion of
towne within « srequeney slic, however, was tye riter byte
Aeviniens o? ts to tele fhe Line value whieh eve the energy
Aumatbution int chice eq parts) fry che rusia! tine mia ee
by the inserter distance. "These two timeslependene chavaete'2h-

Tor mre detals eva
cerning he rediction wud lye of fs! met of ea)

‘One the inportunt ssnmaries fro the stacpoint of perfor
dae i iontSeaton prover, sta be the frequency magi
normale ence ‘Hos bos Touinnensionalzepeeentation with
fhe drs body of dita amd 2W-digtisions reprceentation in the

Enns aor origin svaremt. (Sor Heke, of a

Tents) T—Beaoeanuannioss oy Dara

toy FRmgueyey’sticze
1) Intetostinees
to) REGENCY aH
ere cml mate dive ro emer
(0 ng a nenqevey
{S) Mealy oped erate nee
M34 zum erax avereae weontou, orm, APRIL FL

tccond ect To illustrate how this summary represenation ray Tl
Figa. 24 and b cuh show the murmalised encegae in the freuuenry
margin for ell the usranecs of 4 wor ly apeetc talker. Figure 2a
i for one epear and Fig b ie for urotber. Qualitative sd qcentine
‘ive dferenees between chet »poikns are evdent es siewec: nest
the lative eabesvencse a2 the dient wlterwnen within a spaaker,

‘Rach sezeme for suming Jo Ins data Ted wo sct of !aput
statistics whove values foreach utlranre yrld « veolne eovrspending
or that utterance, ‘Tho sua.teleinvorsed designating exrntn of the
lteerances from ene spexker ax wnnawen End trecting the ramsining
litterances as the reference et of Known uttaranors ta be used for
ppurpows of statisteal estimation, oof the Features of tee rere
popalation

Tus, as shown in Table TT, vorespnting tn the wh reference
ticrance {ie he alr zon) ofa spore wont bythe th alls,
fe woul have e pedimeniannl ne velar opt statistic,

Wah ym

Y= Westone ytd E12,

shore dh th element of the veotor 2 the value of the jh input
Satstie Zor che uth utteraros of the th tallee. ‘There are eallere in
tl wd kava utters irom tho‘ch taker. Then lore wtter:mecs
Of the ss talker may then be wed, = shown in "Table I, to obtain Ure
‘dimensional centnid, ¥; , veel the pp covariance matrix, 8; ,
For he eh tlk,

‘Correponding to on unknown utterenes (2, tho tellue is unknown
end i 0 be identified), whieh a known only to be aa utterance of ome
fone of the tallers i eal one ould silly havea p-imenvional
foneesntation, shown in Table LI ws

Bim teva

Ako <loyn in Table HL are the averll centred 2” snd vo matices
Band W, B isa measure ofthe disperaon of sho speaker centres in
pspnse and fe eallad the beeweulalvers cuvarizace mutex. W i
Fooled naaute of deperion ofthe rescue kaown uleroness anetnl
the talker eentroide ned i Ted sho within takers eoveviance matrix.

fa mectie or ditaase matnire sere delined in the ppaimensional
ne of th inpst sates, thon one coll ealelate the distance of
the unknown, vg, Z', cium cieh of the oetoida, wz. P's, of te
1455

Big Seceuens manic wy yu recy (au dt.
V5 nm saa weausne Perea FOURKAL, AME

diferent takers ead thon wae theo divtanoot to aetgn the unknown
to ore ofthe tlle,

‘AL tie measures of squaeed dlstasee wal in aus work were yoilve
emieetirive quidentin buone, 4 eee whoo typieal mercber sony be
Slaebroialy define! am shown im ita (0 of wale TV. This elo
Ines nob oxy che Lani wineighted Rueliewn squsers distance
(GH — 1) ane the weighted Bulidean eqnaged distance, whieh makes
Sllowaaces for unequal vorianes af the deren varitle, bat seo
Froamures of equared eshwien whieh allow for eortelntions amang the
Cacinbles, Figie & écaling wilh tle esee of wo variables ekows an.
Sppropsice ananner of ensuring equarod stance when the cozela-
tion is postive Aecocding Wy such an elipties) miearure of squared
itunoe, points Ike dy und Py whieh He the ste llipee re eon

dered fo be (he eatse cimanon wway From the ertor C of che ellipa,
ners pt ike ay dere as Which He on the decent lips
fhunbored 1,2 and # are eusiderel n beat increasing dsteneee sway
from C The way Uo aelest thie coiee Zarmally in he definition of
quarod distanoe ie 20 use fur BU the saverse of un estimate of the
fevasience six of The vases.

"Table IV ceo shows thecesprealeations of cbe tebe Mf chet Tend
to chreeequisl Wistenee nssanares Th, Dy ancl Dy shown, eagweively,
ss onuacons (1), (2) <nd (8

“The eboiee of M tht less to 7: wes each taker’ iin. mene
ince matsp viemsaring 2 dae The xnkewn ce thet user's

“Tasun THNonuniox an Famnvanss roa TReexancr ems

© * Sie. — nw. —B;
heat
w ai, where w= Some