SEARCH · PubMed Health

Results for “Speech Intelligibility”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

PubMedDate not supplied

Speech intelligibility and the use of hearing protectors.

On theoretical grounds, it is usually assumed that the use of hearing protectors in a noisy working environment has no influence upon speech intelligibility - in fact, may even increase it. In practice, however, people often do not wear hearing protectors, since these are widely believed to reduce speech intelligibility. In the present article, a description is given of an investigation, carried out among 537 subjects, into the influence of hearing protectors upon the speech intelligibility of people suffering from noise-induced hearing loss. From this analysis, it has become clear that the use of ear-muffs only leads to an improvement in speech intelligibility in persons who, according to their pure-tone audiogram, suffer from relatively small hearing losses. In general, it may be said that an increase in the severity of hearing losses will result in a reduced speech intelligibility.

Adolescent↗

PubMed2000

The speech intelligibility at the opera singing.

The authors investigated the speech intelligibility at opera singing. They analysed several arias sung by soprano voices from Czech opera "Rusalka" (The water Nymph), from Puccini's opera "La Boheme" and several parts of arias from "Il barbiere di Siviglia" sung by baritone, tenor, bass and soprano. The sonographic pictures of selected arias were compared with a subjective evaluation. The difference between both authors was about 70%. The opinion is, that the singer's formant is not the only one problem having its role in the speech intelligibility of opera singing. The important role is played by the ability to change the shape of vocal tract and the ability of rapid and exact articulatory movements. This ability influences the shape of transients that are important at the normal speaking and also in the singing.

Female↗

PubMed1999

A graphical method for calculating the speech intelligibility index and measuring hearing disability from audiograms.

The speech intelligibility index (SII) is interpreted as the proportion of total speech information available to the listener's ear for a given speech material. Consequently, SII varies in the range 0-1. A simple graphical method for determining SII for monaural listening at 1 m distance from a talker producing "average speech" (or PB-words) at normal speech effort is described. The speech area is visualized by 10 x 10 = 100 points in the audiogram form, each point contributing 0.01 to the SII. The SII thus equals 0.01 times the number of points in the audible range. A sensorineural hearing loss gives rise to an additional loss in speech recognition due to reduced frequency discrimination and time resolving ability. This suprathreshold deficit is corrected for, if the SII contribution in each frequency band is multiplied with a hearing threshold level dependent "desensitization factor". The SII is related to the intelligibility of speech, and may be used to evaluate a hearing disability.

Adult↗

PubMed1988

Criterion validity of speech intelligibility rating-scale procedures for the hearing-impaired population.

The criterion validity and reliability of two popular rating-scale procedures for the assessment of the contextual speech intelligibility of hearing-impaired individuals (The NTID Scales) were studied under clinically typical conditions of test administration and evaluation. The criterion measure was a write-down procedure based on subjects' readings of sentence lists chosen from The CID Everyday Sentence lists. Although the results revealed generally high overall validity and reliability coefficients for the two scales, a close examination of the distribution of estimation error over the full range of rating-scale values revealed gross violations of measurement prediction within the clinically most frequent midrange of speech intelligibility. The results indicate that the rating-scale procedure significantly compromises clinical and research classification of an individual's speech intelligibility and that write-down procedures may provide a viable and significantly more accurate alternative for speech intelligibility assessment.

Adult↗

PubMed1977

Audiometric analysis as a predictor of speech intelligibility.

This study examines the usefulness of the audiogram as a predictive instrument in speech intelligibility. Much of the early work on the audiogram centred on speech reception (e.g. Harris, Haines and Myers, 1956) but Montgomery (1967) made a case for the application to speech production especially when profoundly deaf children are involved. Speech intelligibility was measured by playing back to groups of listeners, tapes consisting of sentences read by 15-16-year-old schoolchildren. Listeners had to fill in two missing words in the sentences. Analyses of the pattern of hearing loss, of the loss at individual frequencies and finally, of combinations of the loss at different frequencies were made. The results indicate that in most circumstances, subjects may be placed in four distinguishable groups, separated at 65dB, and 105dB. When the simple mean of five frequency losses, centred on 1,000Hz is taken, five groups have significantly different levels of speech intelligibility.

Adolescent↗

PubMed2006

[Verification of normative values for the Swiss version of the Freiburg speech intelligibility test].

BACKGROUND AND OBJECTIVE: In the Swiss version of the Freiburg speech intelligibility test five test words from the original German recording which are rarely used in Switzerland have been exchanged. Furthermore, differences in the transfer functions between headphone and loudspeaker presentation are not taken into account during calibration. New settings for the levels of the individual test words in the recommended recording and small changes in calibration procedures led us to make a verification of the currently used normative values. PATIENTS AND METHODS: Speech intelligibility was measured in 20 subjects with normal hearing using monosyllabic words and numbers via headphones and loudspeakers. RESULTS: On average, 50% speech intelligibility was reached at levels which were 7.5 dB lower under free-field conditions than for headphone presentation. The average difference between numbers and monosyllabic words was found to be 9.6 dB, which is considerably lower than the 14 dB of the current normative curves. CONCLUSIONS: There is a good agreement between our measurements and the normative values for tests using monosyllabic words and headphones, but not for numbers or free-field measurements.

Adult↗

PubMed1994

Effects of speech intelligibility level on concurrent visual task performance.

Four experiments were performed to determine if changes in the level of speech intelligibility in an auditory task have an impact on performance in concurrent visual tasks. The auditory task used in each experiment was a memory search task in which subjects memorized a set of words and then decided whether auditorily presented probe items were members of the memorized set. The visual tasks used were an unstable tracking task, a spatial decision-making task, a mathematical reasoning task, and a probability monitoring task. Results showed that performance on the unstable tracking and probability monitoring tasks was unaffected by the level of speech intelligibility on the auditory task, whereas accuracy in the spatial decision-making and mathematical processing tasks was significantly worse at low speech intelligibility levels. The findings are interpreted within the framework of multiple resource theory.

Adult↗

PubMed1990

Speech intelligibility enhancement by interaural magnification.

Hearing-impaired persons suffer from loss of speech intelligibility in noisy environments as well as from a decrease in binaural performance (e.g., interaural time and intensity discrimination). In order to improve speech intelligibility for spatially separated signal and noise sources by compensating for the reduced binaural performance, we implemented an algorithm increasing binaural dissimilarity on a digital signal processor. This algorithm is a modification of the proposal by Durlach & Pang (J. Acoust. Soc. Am. 1986; 80: 1849-1850). Speech discrimination experiments were performed under simulated spatial conditions with recordings of the speech material and the interfering noise source using a dummy head. With increasing complexity of the spatial masking condition, the binaural advantage as well as the benefits from the algorithm decreased for normal listeners. For four sensorineurally hearing-impaired listeners, only one spatial condition was tested. In addition, a battery of binaural tests (binaural masking level difference, interaural time and intensity discrimination) was performed. The results indicate that the benefits from the signal-processing technique are correlated with the remaining binaural performance.

Adult↗

PubMedDate not supplied

Effect of cleft type on overall speech intelligibility and resonance.

The main purpose of this study was to measure and compare the effect of an unilateral cleft lip and palate (UCLP) and a bilateral cleft lip and palate (BCLP) on overall speech intelligibility, nasalance and nasality. An additional objective was to compare the nasalance and nasality patterns of cleft palate children with the available normative data for normal children. The subjects were 37 children with an UCLP (19/37) or a BCLP (18/37) with normal cognitive and motor functions and normal hearing levels. All subjects had a non-syndromic cleft, followed the same surgical protocol and did not undergo secondary pharyngeal surgery. To measure and compare the effect of cleft type, objective and subjective assessment techniques were used. For the objective assessment of nasal resonance the nasometer and the mirror-fogging test were used. Nasalance scores were obtained, while patients produced sounds, read three standard passages or repeated sentences focusing on specific consonants. A perceptual evaluation of speech, the Gutzmann (1913) test and the tests of Bzoch (1989) were used as subjective assessment techniques. The perceptual assessment of the overall speech intelligibility was based on the spontaneous speech and reading or repeating of the nasometric sentences. These samples were judged by three speech pathologists using a 4-category nominal scale. A subjective test (Morley, 1945) was used to evaluate the velopharyngeal mechanism. The findings of the present study show no statistically significant differences for nasalance values, nasality and overall speech intelligibility between the UCLP and BCLP children. Significant differences were found between the data of the normal group and the cleft palate children. These differences included nasalance values as well as nasality data and overall speech intelligibility.

Adolescent↗

PubMed1992

Evaluation of the speech intelligibility rating (SIR) test for hearing aid comparisons.

The SIR test was created for use in hearing aid comparisons. The test protocol obtains listener judgments of the intelligibility of connected speech passages. This study was conducted to evaluate the effectiveness of the SIR test in differentiating among hearing aids. Specific research questions were (a) Is the sensitivity of the SIR test sufficient for differentiating among very similar and slightly dissimilar hearing aids? (b) Does the SIR test result in reliable hearing aid rankings? and (c) What are the effects of using shortened connected speech passages? Ten listeners with hearing impairments rated the intelligibility of both full-length and shortened SIR test passages while wearing each of four individually selected hearing aids representing three different frequency/gain prescriptions. Results suggested that the SIR test is capable of differentiating among slightly dissimilar hearing aids and that hearing aid rankings resulting from speech intelligibility ratings were reliable. The decision to use full-length or shortened SIR test passages depends on the outcome the user wishes to maximize. Under the conditions used in this study, maximum sensitivity was achieved with ratings from five shortened passages, whereas maximum reliability was obtained with three full-length passages.

Adult↗

PubMed1993

Syllabic compression and speech intelligibility in hearing impaired listeners.

Syllabic compression has not been shown unequivocally to improve speech intelligibility in hearing-impaired listeners. This paper attempts to explain the poor results by introducing the concept of minimum overshoots. The concept was tested with a digital signal processor on hearing-impaired subjects. The results show that moderate syllabic compression may raise speech intelligibility, as long as overshoots are minimized and relatively short time constants are used. Frequency equalization also contributes to speech intelligibility.

Acoustic Stimulation↗

PubMed2001

Effects of a music therapy voice protocol on speech intelligibility, vocal acoustic measures, and mood of individuals with Parkinson's disease.

This study examined the effects of a Music Therapy Voice Protocol (MTVP) on speech intelligibility, vocal intensity, maximum vocal range, maximum duration of sustained vowel phonation, vocal fundamental frequency, vocal fundamental frequency variability, and mood of individuals with Parkinson's disease. Four female patients, who demonstrated voice and speech problems, served as their own controls and participated in baseline assessment (study pretest), a series of MTVP sessions involving vocal and singing exercises, and final evaluation (study posttest). In study pre and posttests, data for speech intelligibility and all acoustic variables were collected. Statistically significant increases were found in speech intelligibility, as rated by caregivers, and in vocal intensity from study pretest to posttest as the results of paired samples t-tests. In addition, before and after each MTVP session (session pre and posttests), self-rated mood scores and selected acoustic variables were collected. No significant differences were found in any of the variables from the session pretests to posttests, across the entire treatment period, or their interactions as the results of two-way ANOVAs with repeated measures. Although not significant, the mean of mood scores in session posttests (M = 8.69) was higher than that in session pretests (M = 7.93).

Affect↗

PubMed1987

Derivation of primary parameters and procedures for use in speech intelligibility predictions.

The literature on various parameters that appear in the articulation index-type calculations of speech intelligibility is reexamined. Based on the reported data, the best estimates of these parameters and the most appropriate procedures for their use are suggested. These included: (1) the analysis and specification of the importance of various frequency bands to speech intelligibility; (2) the procedures used for measuring threshold and the calculation of threshold-based parameters used for predicting intelligibility of low-level speech; and (3) the calculation and measurement of relevant speech parameters. All results are given so that the calculations can be performed either in critical bands, 1/3 octaves, or octaves.

Algorithms↗

PubMed2004

Speech intelligibility in severe adductor spasmodic dysphonia.

This study compared speech intelligibility in nondisabled speakers and speakers with adductor spasmodic dysphonia (ADSD) before and after botulinum toxin (Botox) injection. Standard speech samples were obtained from 10 speakers diagnosed with severe ADSD prior to and 1 month following Botox injection, as well as from 10 age- and gender-matched healthy adults. This yielded 3 speaking conditions: pre-Botox injection, post-Botox injection, and normal control. Thirty phrases were extracted from the speech samples and arranged in a counterbalanced listening experiment. Thirty students, reporting little experience with distorted speech, served as listeners. Each listener's response was scored for words correctly identified using a liberal scoring criterion yielding a percentage of words correctly identified for each speaker. The results indicated that the speakers with ADSD were significantly more intelligible in the post-Botox condition than in the pre-Botox condition. The results also indicated that healthy speakers were significantly more intelligible than the speakers in both the pre- and post-Botox conditions. In general, these results indicated that intelligibility is affected in severe ADSD and that the use of Botox injection in ADSD improves intelligibility scores. However, the results also indicated that the use of Botox injection does not result in speech intelligibility similar to that of normal, non-ADSD speakers.

Acoustic Stimulation↗

PubMed1991

Computerized measurement of speech intelligibility. I. Development of system and procedures.

An experimental system for the measurement of speech intelligibility has been developed. It uses a Personal Computer (PC), together with appropriate software to handle playback of test words in carrier phrases, presented in a 'closed response' test condition. Information about the intelligibility, based on the correct responses and the confusions, is immediately available due to simultaneous collecting and sorting of subjects' responses. The system works satisfactorily and reliably and has been well received by experimenters as well as by adult test subjects in the age range 18-70 years. From a new Danish standard speech material for audiological purposes, a Multiple Choice speech intelligibility test has been devised. The test is called 4AFC (Four Alternative Forced Choice) and is based on monosyllabic words with consonant confusions. Normative data for the 4AFC test, obtained with the computerized system, are presented in an accompanying paper.

Adolescent↗

PubMed2006

Prediction of speech intelligibility in spatial noise and reverberation for normal-hearing and hearing-impaired listeners.

Binaural speech intelligibility of individual listeners under realistic conditions was predicted using a model consisting of a gammatone filter bank, an independent equalization-cancellation (EC) process in each frequency band, a gammatone resynthesis, and the speech intelligibility index (SII). Hearing loss was simulated by adding uncorrelated masking noises (according to the pure-tone audiogram) to the ear channels. Speech intelligibility measurements were carried out with 8 normal-hearing and 15 hearing-impaired listeners, collecting speech reception threshold (SRT) data for three different room acoustic conditions (anechoic, office room, cafeteria hall) and eight directions of a single noise source (speech in front). Artificial EC processing errors derived from binaural masking level difference data using pure tones were incorporated into the model. Except for an adjustment of the SII-to-intelligibility mapping function, no model parameter was fitted to the SRT data of this study. The overall correlation coefficient between predicted and observed SRTs was 0.95. The dependence of the SRT of an individual listener on the noise direction and on room acoustics was predicted with a median correlation coefficient of 0.91. The effect of individual hearing impairment was predicted with a median correlation coefficient of 0.95. However, for mild hearing losses the release from masking was overestimated.

Acoustic Stimulation↗

PubMed1999

Speech intelligibility and localization in a multi-source environment.

Natural environments typically contain sound sources other than the source of interest that may interfere with the ability of listeners to extract information about the primary source. Studies of speech intelligibility and localization by normal-hearing listeners in the presence of competing speech are reported on in this work. One, two or three competing sentences [IEEE Trans. Audio Electroacoust. 17(3), 225-246 (1969)] were presented from various locations in the horizontal plane in several spatial configurations relative to a target sentence. Target and competing sentences were spoken by the same male talker and at the same level. All experiments were conducted both in an actual sound field and in a virtual sound field. In the virtual sound field, both binaural and monaural conditions were tested. In the speech intelligibility experiment, there were significant improvements in performance when the target and competing sentences were spatially separated. Performance was similar in the actual sound-field and virtual sound-field binaural listening conditions for speech intelligibility. Although most of these improvements are evident monaurally when using the better ear, binaural listening was necessary for large improvements in some situations. In the localization experiment, target source identification was measured in a seven-alternative absolute identification paradigm with the same competing sentence configurations as for the speech study. Performance in the localization experiment was significantly better in the actual sound-field than in the virtual sound-field binaural listening conditions. Under binaural conditions, localization performance was very good, even in the presence of three competing sentences. Under monaural conditions, performance was much worse. For the localization experiment, there was no significant effect of the number or configuration of the competing sentences tested. For these experiments, the performance in the speech intelligibility experiment was not limited by localization ability.

Adolescent↗

PubMed2006

Speech intelligibility in noise using throat and acoustic microphones.

INTRODUCTION: Helicopter cockpits are very noisy and this noise must be reduced for effective communication. The standard U.S. Army aviation helmet is equipped with a noise-canceling acoustic microphone, but some ambient noise still is transmitted. Throat microphones are not sensitive to air molecule vibrations and thus, transmittal of ambient noise is reduced. It is possible that throat microphones could enhance speech communication in helicopters, but speech intelligibility with the devices must first be assessed. In the current study, speech intelligibility of signals generated by an acoustic microphone, a throat microphone, and by the combined output of the two microphones was assessed using the Modified Rhyme Test (MRT). METHODS: Stimulus words were recorded in a reverberant chamber with ambient broadband noise intensity at 90 and 106 dBA. Listeners completed the MRT task in the same settings, thus simulating the typical environment of a rotary-wing aircraft. RESULTS: Results show that speech intelligibility is significantly worse for the throat microphone (average percent correct = 55.97) than for the acoustic microphone (average percent correct = 69.70), particularly for the higher noise level. In addition, no benefit is gained by simultaneously using both microphones. A follow-up experiment evaluated different consonants using the Diagnostic Rhyme Test and replicated the MRT results. DISCUSSION: The current results show that intelligibility using throat microphones is poorer than with the use of boom microphones in noisy and in quiet environments. Therefore, throat microphones are not recommended for use in any situation where fast and accurate speech intelligibility is essential.

Acoustics↗