The relation between intelligibility and the acoustic characteristics of deaf speech: An acoustic analysis of the vowels /i/ and /aw/, and nasals

This paper discusses a study that examined acoustic measures and the relationship to speech intelligibility of children with cochlear implants.

Predicting for the hearing impaired the intelligibility of different kinds of speech materials

This paper discusses a study to define the function relating the scores for hearing impaired listeners on four different speech materials.

Validation of a speech intelligibility measure for profoundly deaf children

This paper reviews a study to validate a speech intelligibility measure for profoundly deaf children.

Factors relating to the intelligibility of the speech of deaf children

This paper reviews a study of the speech intelligibility of deaf children to listeners with normal hearing.

Effect of amplification bandwidth on speech intelligibility

This paper was a study to examine the effect of bandlimiting on speech intelligibility.

Binaural prediction of speech intelligibility in reverberant rooms with multiple noise sources

When speech is in competition with interfering sources in rooms, monaural indicators of intelligibility fail to take account of the listener’s abilities to separate target speech from interfering sounds using the binaural system. In order to incorporate these segregation abilities and their susceptibility to reverberation, Lavandier and Culling [J. Acoust. Soc. Am. 127, 387–399 (2010)] proposed a model which combines effects of better-ear listening and binaural unmasking. A computationally efficient version of this model is evaluated here under more realistic conditions that include head shadow, multiple stationary noise sources, and real-room acoustics. Three experiments are presented in which speech reception thresholds were measured in the presence of one to three interferers using real-room listening over headphones, simulated by convolving anechoic stimuli with binaural room impulse-responses measured with dummy-head transducers in five rooms. Without fitting any parameter of the model, there was close correspondence between measured and predicted differences in threshold across all tested conditions. The model’s components of better-ear listening and binaural unmasking were validated both in isolation and in combination. The computational efficiency of this prediction method allows the generation of complex “intelligibility maps” from room designs. © 2012 Acoustical Society of America

Effects of hearing protector devices on speech intelligibility

The purpose of this study was to determine the influence of hearing protection devices (HPDs) on the understanding of speech in young adults with normal hearing, both in a silent situation and in the presence of ambient noise. The experimental research was carried out with the following variables: five different conditions of HPD use (without protectors, with two earplugs and with two earmuffs); a type of noise (pink noise); 4 test levels (60, 70, 80 and 90 dB[A]); 6 signal/noise ratios (without noise, + 5, + 10, zero, - 5 and - 10 dB); 5 repetitions for each case, totalling 600 tests with 10 monosyllables in each one. The variable measure was the percentage of correctly heard words (monosyllabic) in the test. The results revealed that, at the lowest levels (60 and 70 dB), the protectors reduced the intelligibility of speech (compared to the tests without protectors) while, in the presence of ambient noise levels of 80 and 90 dB and unfavourable signal/noise ratios (0, -5 and -10 dB), the HPDs improved the intelligibility. A comparison of the effectiveness of earplugs versus earmuffs showed that the former offer greater efficiency in respect to the recognition of speech, providing a 30% improvement over situations in which no protection is used. As might be expected, this study confirmed that the protectors' influence on speech intelligibility is related directly to the spectral curve of the protector's attenuation. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

[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.

Speech Intelligibility in Noise With a Single-Unit Cochlear Implant Audio Processor.

INTRODUCTION The Rondo is a single-unit cochlear implant (CI) audio processor comprising the identical components as its behind-the-ear predecessor, the Opus 2. An interchange of the Opus 2 with the Rondo leads to a shift of the microphone position toward the back of the head. This study aimed to investigate the influence of the Rondo wearing position on speech intelligibility in noise. METHODS Speech intelligibility in noise was measured in 4 spatial configurations with 12 experienced CI users using the German adaptive Oldenburg sentence test. A physical model and a numerical model were used to enable a comparison of the observations. RESULTS No statistically significant differences of the speech intelligibility were found in the situations in which the signal came from the front and the noise came from the frontal, ipsilateral, or contralateral side. The signal-to-noise ratio (SNR) was significantly better with the Opus 2 in the case with the noise presented from the back (4.4 dB, p < 0.001). The differences in the SNR were significantly worse with the Rondo processors placed further behind the ear than closer to the ear. CONCLUSION The study indicates that CI users with the receiver/stimulator implanted in positions further behind the ear are expected to have higher difficulties in noisy situations when wearing the single-unit audio processor.

Speech Intelligibility in Noise With a Pinna Effect Imitating Cochlear Implant Processor.

OBJECTIVE To evaluate the speech intelligibility in noise with a new cochlear implant (CI) processor that uses a pinna effect imitating directional microphone system. STUDY DESIGN Prospective experimental study. SETTING Tertiary referral center. PATIENTS Ten experienced, unilateral CI recipients with bilateral severe-to-profound hearing loss. INTERVENTION All participants performed speech in noise tests with the Opus 2 processor (omnidirectional microphone mode only) and the newer Sonnet processor (omnidirectional and directional microphone mode). MAIN OUTCOME MEASURE The speech reception threshold (SRT) in noise was measured in four spatial settings. The test sentences were always presented from the front. The noise was arriving either from the front (S0N0), the ipsilateral side of the CI (S0NIL), the contralateral side of the CI (S0NCL), or the back (S0N180). RESULTS The directional mode improved the SRTs by 3.6 dB (p < 0.01), 2.2 dB (p < 0.01), and 1.3 dB (p < 0.05) in the S0N180, S0NIL, and S0NCL situations, when compared with the Sonnet in the omnidirectional mode. There was no statistically significant difference in the S0N0 situation. No differences between the Opus 2 and the Sonnet in the omnidirectional mode were observed. CONCLUSION Speech intelligibility with the Sonnet system was statistically different to speech recognition with the Opus 2 system suggesting that CI users might profit from the pinna effect imitating directionality mode in noisy environments.

Objective measurement of voice channel intelligibility /

Mode of access: Internet.

Impact of pallidotomy on physiological articulation function and speech intelligibility in Parkinsons disease

The objective of this study was to evaluate the effects of posteroventral pallidotomy on perceptual and physiological measures of articulatory function and speech intelligibility in Parkinson disease (M). The study examined 11 participants with M who underwent posteroventral pallidotomy Physiological measures of hp and tongue function. and perceptual measures of speech intelligibility were obtained prepallidotomy and 3 months postpallidotomy. The participants with PD were also assessed on the Unified Parkinsons Disease Rating Scale (UPDRS Part III) In addition, the study included a group of 16 participants with PD who did not undergo pallidotomy and a group of 30 nonneurologically impaired participants. Analyses of physiological articulatory function and speech intelligibility did not reveal corresponding improvements in motor speech function as observed in general limb motor function postpallidotomy. Overall, individual reliable change analyses revealed that the majority of surgical PD participants demonstrated no reliable change on perceptual and physiological measures of articulation. The cur rent study revealed preliminary evidence that articulatury function and speech intelligibility did not change following posteroventral pallidotomy in a group of individuals with PD.

The intelligibility of noise-vocoded speech:spectral information available from across-channel comparison of amplitude envelopes

Noise-vocoded (NV) speech is often regarded as conveying phonetic information primarily through temporal-envelope cues rather than spectral cues. However, listeners may infer the formant frequencies in the vocal-tract output—a key source of phonetic detail—from across-band differences in amplitude when speech is processed through a small number of channels. The potential utility of this spectral information was assessed for NV speech created by filtering sentences into six frequency bands, and using the amplitude envelope of each band (=30 Hz) to modulate a matched noise-band carrier (N). Bands were paired, corresponding to F1 (˜N1 + N2), F2 (˜N3 + N4) and the higher formants (F3' ˜ N5 + N6), such that the frequency contour of each formant was implied by variations in relative amplitude between bands within the corresponding pair. Three-formant analogues (F0 = 150 Hz) of the NV stimuli were synthesized using frame-by-frame reconstruction of the frequency and amplitude of each formant. These analogues were less intelligible than the NV stimuli or analogues created using contours extracted from spectrograms of the original sentences, but more intelligible than when the frequency contours were replaced with constant (mean) values. Across-band comparisons of amplitude envelopes in NV speech can provide phonetically important information about the frequency contours of the underlying formants.

Teaching pronunciation:a case for a pedagogy based upon intelligibility

This thesis examines the main aim of teaching pronunciation in second language acquisition in the Syrian context. In other words, it investigates the desirable end point, namely: whether it is native-like accent, or intelligible pronunciation. This thesis also investigates the factors that affect native-like pronunciation and intelligible accent. It also analyses English language teaching methods. The currently used English pronunciation course is examined in detail too. The aim is to find out the learners’ aim of pronunciation, the best teaching method for achieving that aim, and the most appropriate course book that fulfils the aim. In order to find out learners’ aim in pronunciation, a qualitative research is undertaken. The research takes advantage of some aspects of case study. It is also supported by a questionnaire to gather data. The result of this research can be regarded as an attempt to bring the Syrian context to the current trends in the teaching of English pronunciation. The results show that learners are satisfied with intelligible pronunciation. The currently used teaching method (grammar-translation method) may be better replaced by the (communicative approach) which is more appropriate than the currently used method. It is also more effective to change the currently used book to a new one that corresponds to that aim. The current theories and issues in teaching English pronunciation that support learners’ intelligibility will be taken into account in the newly proposed course book.