Magnitude-Estimation Scaling of Speech Intelligibility: Effects of Listeners' Experience and Semantic-Syntactic Context

Abstract

Fifteen speech-language pathologists with extensive experience judging speakers' intelligibility and 15 control subjects with no such previous experience provided magnitude-estimation responses for two sets of nine audiotaped speech samples. These samples were three utterances composed of a group of 17 words that contained all the consonant phonemes of English. These words were arranged to form a set of either meaningful or nonsense utterances. Nine separate versions of both the meaningful and nonsense utterances were created by systematically increasing the number of phonemes produced incorrectly on each of the nine recordings. The analysis indicated no significant difference between the magnitude-estimation scaling responses of experienced and inexperienced listeners. A significant over-all difference was found for listeners' responses to meaningful versus nonsense utterances. The advantages of magnitude-estimation scaling as a measure of speakers' intelligibility are discussed.

Medidas de inteligibilidade nos distúrbios da fala: revisão crítica da literatura

“…The methods used to assess intelligibility of individuals with speech disturbances can be divided into two groups: scaling methods and item identification methods (1). Scaling methods encompass: direct magnitude estimate (12,19,22), interval scaling (7,(23)(24)(25)(26), rating of speech sample pairs(1), percentage estimates (7,17) and the analogic visual scale (20). Item identification methods involve multiple formats according to the type of response required to identify speech stimuli.…”

“…Listeners subsequently establish values for the speech samples of the subjects assessed, which represent the degree of intelligibility of these utterances in relation to the standard sample (22). In one variant of this method, the listener is asked to designate a value to the first sample assessed, which is then taken as a reference for assessing the remaining items (12,19).…”

“…Besides the issue of the diversity of methods available, another important aspect is the influence certain variables can have on these measures (1,2). A number of studies on the intelligibility of speech have addressed the effects of several of these variables including: the task employed for speech sample collection(5), the stimulus type used (3,4,(6)(7)(8)(9)(10)(11)(12)(13)(14), the mode in which samples are presented (11,13,(15)(16)(17), the response type required to identify the stimuli (7,18), the type of transcription analysis(2), the gender of the listener or rater (13,19), or their familiarity with the speaker(s) (9,11,13,20,21)).…”

A Pilot Study: Normative Data on the Intelligibility of 3 1/2 Year Old Children

“…As has been stated by many researchers (Connolly, .1986;Ellis & Fucci, 1991;Garret & Moran, 1992;Gordon-Brannan, 1994;Grunwell, 1981;Kent et al, 1994),…”

“…The influences of experienced and inexperienced listeners was also addressed by Ellis and Fucci (1991). The question they attempted to answer was-whether to use one or both types of listeners when evaluating speakers• intelligibility through the use of magnitude-estimation scaling.…”