Linguistic profiling is the practice of identifying the social characteristics of an individual based on auditory cues, in particular dialect and accent. The theory was first developed by Professor John Baugh to explain discriminatory practices in the housing market based on the auditory redlining of prospective clientele by housing administrators. Linguistic profiling extends to issues of legal proceedings, employment opportunities, and education. The theory is frequently described as the auditory equivalent of racial profiling. The bulk of the research and evidence in support of the theory pertain to racial and ethnic distinctions, though its applicability holds within racial or ethnic groups, perceived gender and sexual orientation, and in distinguishing location of geographic origin.

Baugh's theory is distinct from linguistic profiling as defined by Hans van Halteren from the University of Nijmegen in the Netherlands. Van Halteren's theory deals with the categorization of linguistic features for the purposes of author identification and verification from a text, not necessarily specifically addressing the socially defined categories within which they are included.

Discrimination

An important distinction exists between the many uses of linguistic profiling and the potential for discriminatory treatment. The power to determine origin or racial identity based on speech can be utilized without overt discrimination, as argued in several court cases where voice was used in the prosecution of a suspect. The negative effects of linguistic profiling are seen in the practice of denying housing or employment based on stereotypes associated with dialect and/or accent. Further negative practices are associated with education and general treatment of individuals speaking stigmatized dialects. A more positive view of the practice is found in Baugh's description of expressions of ethnic pride.Baugh, John, Linguistic Profiling, in Black Linguistics: Language, Society, and Politics in Africa and the Americas 155, 155-63 (Sinfree Makoni et al. eds., 2003). Though average people have been shown to be well equipped in measuring social characteristics by means of speech, the failings of those unfamiliar with a speech community and the capability of manipulation of speech should be taken into account when determining the unbiased use of linguistic profiling.Salaberry, M. Rafael. Language allegiances and bilingualism in the US. Clevedon: Multilingual Matters, 2009.

Ascribed categories

Race

Between racial groups

The primary research done on linguistic profiling was a result of linguist John Baugh's experience searching for housing as an African American. Baugh found a discrepancy between the proclaimed availability of an apartment in a phone interview, in which he utilized Standard American English, and its apparent unavailability upon a face-to-face meeting with the landlord. The changed conception of the housing administrator between auditory and visual cues pointed to overt discrimination based on race.

Baugh, Purnell, and Idsardi completed a set of four experiments based on the identification of dialects in American English. The resulting findings were:

Discrimination based on dialect does occur. It is possible for naïve listeners to identify ethnicity through speech. Very little speech is required to make an accurate identification.

Discrimination based on American English dialect

The first experiment involved a series of telephone surveys in which a single speaker requested housing in the chosen dialects of Chicano English, African American Vernacular English, and Standard American English. Each landlord selected was subject to three requests in these three dialects, and the correlating negative and positive responses to call-back appointments were shown to favor speakers of Standard American English. Their findings for the percent of call-backs for the two cities of Palo Alto and Woodside, which had African American and Hispanic Americans populations less than 5%, were as follows: Geographic location Standard American English Chicano American English African American Vernacular English Palo Alto 63.1% 31.9% 48.3% Woodside 70.1% 21.8% 28.7%

Of the four geographical locations chosen in the study, those with the lowest populations of African Americans and Hispanic Americans were shown to have the greatest bias towards the non-standard dialects.

Distinguishing dialect

In order to determine the ability of people to distinguish dialect, a separate experiment was conducted. Fifty undergraduate students, all Caucasian speakers of Standard American English, were asked to identify the ethnicity behind a recording of the word "hello" spoken in either Chicano English, African American Vernacular English, and Standard American English.

Respondents were able to identify the correct dialect more than 70% of the time. Chicano English was found to be more easily identifiable than African American Vernacular English.

Within racial groups While much evidence has been collected describing linguistic profiling between racial groups within a speech community, linguistic profiling also extends to members within a racial or ethnic group. This is evidenced by a study conducted by Jaquelyn Rahman describing the perception of middle class African Americans to African American Vernacular English, or AAVE, and Standard American English. She found that subjects associated AAVE with their heritage, while perceiving African Americans who used Standard English as "acting white".

Chinese American and Korean American English speech An intra-racial distinction was researched by Newman and Wu, who conducted a study in which subjects were asked to identify various speakers based on race; the speakers included Latinos, African Americans, Chinese Americans, Korean Americans, and white speakers. Listeners tended to successfully categorize speakers as Latino, African American, white or Asian; often, they could not discern between Chinese American and Korean American English speakers, although phonetic differences exist.

It has been found that Korean American and Chinese American English speakers tend to have a longer voice onset time (VOT), or the length of time between a plosive and voicing, than other speakers of Standard American English. Furthermore, Korean American speakers tend to have a longer VOT than Chinese American speakers. This distinction is apparent when considering the VOT of the phonemes [ph], [kh] and [th]. Phoneme Standard VOT Chinese American VOT Korean American VOT [ph] 58 ms 77 ms 91 ms [kh] 70 ms 75 ms 94 ms [th] 80 ms 87 ms 126 ms

Another distinction between Korean American and Chinese American English speakers can be found in the timing of spoken syllables, or rhythm. Chinese American speakers (in particular, males), tended to speak with a more regular timing of syllables than Korean American speakers.

Gender and sexual orientation Linguistic profiling also applies to gender and sexual orientation. Benjamin Munson conducted a study in which naïve listeners were asked to distinguish between heterosexual male and female speakers, and gay male and bisexual or lesbian female speakers. He found that listeners tended to classify male and female speakers by masculinity and femininity, respectively; male speakers were perceived as gay if they sounded less masculine, while female speakers were identified as bisexual or lesbian if they sounded less feminine.

Perceived femininity Linguistic features of perceived femininity include the following: Front vowels are produced with a higher F1 harmonic frequency Back vowels are produced with a higher F2 harmonic frequency Female speakers perceived as bisexual or lesbian exhibited opposite characteristics. Furthermore, speakers who are identified as bisexual or lesbian are not necessarily perceived as masculine.

Perceived masculinity Linguistic features of perceived masculinity include the following: Low vowels are produced with a higher F1 harmonic frequency Back vowels are produced with a lower F2 harmonic frequency A negative /s/ skew, or a skew towards the first harmonic frequency F1 Male speakers perceived as gay tended to exhibit opposite characteristics.

In addition, male speakers who were perceived as gay exhibited greater breathiness and hyperarticulation of stressed syllables than male speakers who were perceived as heterosexual. Speakers who are identified as gay are not necessarily perceived as feminine.

Geographic origin Linguistic profiling occurs beyond the spheres of race and ethnicity in the identification of geographic origin. Indeed, evidence suggests that listeners may successfully categorize speakers based upon dialect. Clopper and Pisoni (2003) found that naïve (or inexperienced) listeners could successfully categorize speakers as hailing from New England, the South, or the West, but had greater difficulty discerning geographic origin when a larger number of dialects were provided: New England, North, North Midland, South Midland, South, West, New York City, or Army Brat. Listeners were only able to identify speakers correctly 30% of the time. They also found evidence suggesting that residential history of the listener affected speaker categorization, and that listeners tended to use a small set of phonetic cues to make these distinctions.

Utah English Baker et al. had similar findings in a study in which Utah residents and non-Utah residents were asked to discern the degree of residency of a sample of speakers. Perhaps unsurprisingly, they found that Utah residents and western non-Utah residents tended to correctly identify speakers as being from Utah; the difficulty of other non-Utah residents in identifying Utah speakers was attributed to lack of expertise. However, the western non-Utah residents tended to use more stereotypical phonetic cues to identify speakers than Utah residents. Such findings point to the importance of experience when correctly identifying dialect or region of origin.

Mergers Speakers of Utah English tend to utilize more mergers than speakers of Western American English; this is to say that speakers of Utah English will pronounce certain phonemes, that are distinct in Western American English, the same way. Some examples include fail-fell, pool-pull, card-cord, pin-pen and heel-hill. Such mergers are used more by older speakers.

In institutions

Legal system

O. J. Simpson murder trial A well-known example of the identification of race based on auditory sample in a legal setting occurred during the prosecution of O.J. Simpson. A witness testified against Simpson based on his memory of hearing a "male Black" voice. The objection of Simpson’s lawyer, Mr. Cochran, was overruled by the presiding judge.

Sanchez v. People A major precedent was formed on the use of linguistic profiling in the case of Sanchez v. People. A witness testified against a suspect based on his overhearing of an argument between two apparent Spanish speakers where the killer was identified as having a Dominican rather than a Puerto Rican accent. The New York Superior Court ruled that distinguishing between accents was permissible based on the fact that "human experience has taught us to discern the variation in the mode of speech of certain individuals." The court found that a certain degree of familiarity with the accents and dialects of a region or ethnic group qualified an individual to identify ethnicity or race in a court based on auditory evidence.

Clifford v. Kentucky