Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Speech Intelligibility”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 253 records · Page 14Linked to original sources
PubMed1996

[Articulatory capacity and intelligibility of speech of patients with carcinomas of the mouth cavity. A comparison of pre- and postoperative results of various reconstruction techniques].

Radical orofacial tumor resections often result in speech and swallowing dysfunctions. Thus, both communication ability and life quality can be markedly impaired in patients. Dysfunction is mostly related to the amount of tissue removed and the reconstruction technique used. In this prospective study, pre- and postoperative speech intelligibility following reconstruction with either local grafts, free jejunal flaps or myocutaneous/fasciocutaneous flaps was examined by subjective assessment of monosyllables chosen from the Freiburg audiometry test ("reverse speech intelligibility test"). It was shown that linguodental affricates and dorsofaucal plosives were especially affected, even preoperatively, in patients with T3 and T4 tumors, while additional deterioration of speech function occurred postoperatively. When comparing reconstruction techniques, use of local grafts showed less postoperative deterioration in the patients with T3 and T4 tumors (expert rating/student rating -5.0% +/- (-3.8%), whereas impairment was much more evident when jejunal flaps (expert rating/student rating -27.9% +/- (-35.1%) and myocutaneous and faciocutaneous flaps (expert rating/student rating -34.2% +/- (-48.1%) were used. Results demonstrated that patients should be informed about negative side effects following radical tumor resections and reconstructions of large tissue defects. Surgery should avoid marked motor and sensory nerve lesions whenever possible. Before speech therapy is begun, speech function should be examined carefully. Speech intelligibility should also be documented, e.g. with audio tapes, for quality assessment.

Articulation Disorders↗
PubMed1979

Effects of phase manipulation on speech intelligibility through communication headsets.

A masking level difference (MLD) paradigm was established by rewiring the earphones of a communications headset out-of-phase. Essentially no release from masking could be measured, however, on a crew of listeners in the cabin of light aircraft. The experiment was replicated in the laboratory so that the exact phase of the aircraft noise masker could be controlled. The substantial MLD obtained in this environment led to the conclusion that the noise reaching the ear in the cockpit was of random phase, which almost eliminates the MLD. Therefore, rewiring headsets out-of-phase provides no advantage in intelligibility.

Adult↗
PubMed1998

Evaluation of the effect of speech-rate slowing on speech intelligibility in noise using a simulation of cochlear hearing loss.

The effect of digital processing, which slows the speed of speech (speech-rate) without changing its pitch, has been examined. The processing is intended to make speech communication easier by allowing more time for cognitive processing when the listening situation is difficult, for example, when listening to a foreign language, or when the user has a hearing loss. The speech-rate slowing makes use of a pitch-synchronous partial expansion of the waveform in the time domain. The processing was evaluated using a simulation of hearing loss which has been shown to lead to reduced intelligibility for normally hearing subjects. The simulation included the major consequences of cochlear hearing loss; loudness recruitment, threshold elevation, and reduced frequency selectivity. Two simulations were used: a moderate flat hearing loss with auditory filters broadened by a constant factor of three (B3R2); and the same loss with linear amplification applied prior to the simulation processing (B3R2+). Two expansion rates were used for the speech-rate slowing, 1.25 and 1.50. The intelligibility of sentences in speech-shaped noise was measured. For both simulation conditions, the speech-rate slowing did not give any improvement in intelligibility. Rather, in condition B3R2+ the slowing produced statistically significant deleterious effects on intelligibility. The results suggest that artificial speech-rate slowing will not improve the intelligibility of speech in noise for hearing-impaired people who have the type of cochlear damage simulated in this test.

Adult↗
PubMed1982

Sentences for testing speech intelligibility in noise.

A list of ten spoken Swedish sentences was computer edited to obtain new lists with exactly the same content of sound, but with new sentences. A noise was synthesized from the speech material by the computer to produce exactly the same spectrum of speech and noise. The noise was also amplitude modulated by a low frequency noise to make it sound more natural. This material was tested monaurally on 20 normal-hearing subjects. The equality in intelligibility of some of the lists was investigated. Repeated threshold measurements in noise showed a standard deviation of 0.44 dB when the learning effect was outbalanced. Only a small part of the learning effect was due to learning of the word material. Intelligibility curves fitted to the data points in noise and without noise showed maximum steepnesses of 25 and 10%/dB respectively. At constant signal to noise ratio (S/N) the best performance was achieved at a speech level of 53 dB.

Adolescent↗
PubMed1991

Computerized measurement of speech intelligibility. II. Normative data from a 'closed response' test.

A Danish Four Alternative Forced Choice (4AFC) test was presented to normal-hearing and cochlearly hearing-impaired listeners in two background noises: a modulated, speech-spectrum-shaped noise and an 8-persons babble noise. At the presentation to the hearing-impaired subjects the test signals were given a frequency-dependent amplification in accordance with the POGO-fitting method. Normative data are presented which indicate that 4AFC is a valid test in spite of lack of homogeneity between the alternatives allowed. On the other hand, a learning effect is demonstrated which affects the reliability. A computer-assisted analysis of the obtained consonant confusions reveals a predominance of confusions among initial consonants having the same voicing.

Adult↗
PubMed1988

Speech intelligibility in difficult signal/noise circumstances.

In practice, subjects wearing ear protectors often give contradictory statements about the possible distorting effects of ear protectors. We tried to simulate some difficult background circumstances by arranging five different signal/background noise combinations (five S/N ratios). Speech discrimination tests made in these circumstances with and without ear protectors could reflect the real capacity to understand orders or messages in difficult hearing situations. 52 Finnish speaking conscripts with normal hearing from 18 to 24 years age were selected to participate in the test on a day without any noisy training duties. The test words in the Finnish speech discrimination test in combination with corresponding white noise were produced by equipment consisting of a high quality tape recorder, an audiometer, an amplifier and loud speakers. The test were performed individually in free field in a sound proof room in the Hearing Centre of the University Central Hospital of Oulu. The subjects listened to the test words with all the S/N ratios [S/N = 60/70, 55/70, 65/70, 60/75 and 65/75 dB (A)] with and without ear protectors. At the signal/noise ratios 60/70 and 60/75 dB the words were perceived relatively poorly with and without hearing protectors. At the signal/noise levels of 65/70 and 65/75 dB the protectors turned out to produce highly significantly better word discrimination. At the signal/noise level of 55/70 dB the discrimination is very poor in both cases but significantly better without ear protectors.

Adult↗
PubMed1978

The influence of attack time and release time on speech intelligibility. A study of the effects of AGC on normal hearing and hearing impaired subjects.

Automatic gain control may be used in hearing aids intended for different types and degrees of hearing loss; to average the levels, to reduce the dynamics of speech or to set the maximum output level of the hearing aid without adding nonlinear distortion. Our study concerns hearing impaired listeners with recruitment. A group of normal hearing subjects was used as a control group. The compression was introduced over a laboratory unit. The compression ratio was set to 30:5 dB. A fixed ratio between the attack time and the release time, tr = 200 x ta, was used. The values used varied from 0.05 to 5 ms for ta and 10 - 1000 ms for tr. The speech material was nonsense syllables of the CVC type presented with S/N = 60 dB and S/N = 5 dB. With S/N = 5 dB a significant deterioration of the discrimination of the nonsense syllables was found at time constant combination ta = 5 ms and tr = 1000 ms. No statistically significant difference in discrimination was found between the different combinations of attack and release times for the S/N = 60 dB condition neither for the normal hearing nor for the hearing impaired group.

Hearing Aids↗
PubMed1989

[Speech intelligibility in various types of obturators constructed after maxillary resections].

Six patients who had undergone partial maxillary resection for the removal of oral neoplasms were studied. For each patient two types of obturators were made one being buccal flange and the other hollow-bulb. Speech evaluations were made under three conditions: 1- with the hollow-bulb 2- with the buccal flange and 3- with no obturator. Speech evaluations were made both audiovisually and from tape recordings. In both audiovisual and tape recorded speech evaluations, the buccal flange obturator produced speech which was significantly superior to speech with hollow-bulb obturator.

Humans↗
PubMedDate not supplied

The effect on speech intelligibility of varying compression time constants in a digital hearing aid.

The identification of nonsense syllables in quiet and in three types of background (babble, cafeteria and single female speaker) was measured using four hearing aid compression algorithms differing in attack and release time constants, and using linear amplification. The speech level was always 65 dB SPL. The compression algorithms, which were implemented in a Phonak Claro ITE hearing aid, were: (1) 'very fast'--the attack time was 8 ms and the release time was 32 ms, for all 20 channels; (2) 'slow-fast'--the attack and release times decreased from 500 ms for low frequencies to about lOOms for high frequencies; (3) 'fast-slow'-the attack and release times increased from about 50ms for low frequencies to 500 ms for high frequencies; and (4) 'slow + fast'-a very slow-acting gain control signal was combined with a fast-acting gain control signal, for each channel in a 10-channel system. Acoustical stimuli were presented monaurally via a circumaural headphone mounted over the hearing aid. The linear condition did not use the Claro aid; instead, the signal was digitally filtered to implement the Cambridge formula prior to delivery via the earphone. Five subjects with moderate sensorineural hearing loss were tested in a counter-balanced order across conditions. In quiet, performance was best for linear amplification and worst for the slow + fast algorithm. In the presence of background sounds, the highest scores were obtained with the linear-gain Cambridge formula implemented via headphones; a supplementary experiment suggested that this was due to the greater high-frequency gain resulting from the use of this formula. No significant differences were found between scores for the different compression algorithms. We conclude that the intelligibility of speech at a fixed level, presented in background sounds, is not markedly affected by rather substantial variations of the time constants in a multichannel compression system.

Aged↗
PubMedDate not supplied

[Relation between comfortable loudness and maximal speech intelligibility in children with sensorineural hearing loss].

The levels of comfortable loudness and those of maximal intelligibility were evaluated in 88 schoolchildren with dull hearing (20-90 dB reduction). All the examinees had the levels of comfortable loudness in the range of the maximal intelligibility, this permitting it to be a criterion in determination of optimal amplification in hearing aids. A significant correlation exists between comfortable loudness and hearing threshold at 500 Hz frequency, mean hearing threshold in the range of the principal speech frequencies 500-2000 Hz and in the range of the safest speech frequencies 250-1000 Hz. However, the range of the individual values of comfortable speech intensity in the same hearing thresholds proved to be 15-25 dB for one-syllable words and 20-40 dB for the standard speech tables making it impossible to recommend the threshold parameters for calculation of optimal intensity of the speech to receive. The most reliable way to do this is the adjustment of the speech loudness level by subjective sensation of the child.

Audiometry, Speech↗
PubMed2006

Effect of masker type and age on speech intelligibility and spatial release from masking in children and adults.

Speech recognition in noisy environments improves when the speech signal is spatially separated from the interfering sound. This effect, known as spatial release from masking (SRM), was recently shown in young children. The present study compared SRM in children of ages 5-7 with adults for interferers introducing energetic, informational, and/or linguistic components. Three types of interferers were used: speech, reversed speech, and modulated white noise. Two female voices with different long-term spectra were also used. Speech reception thresholds (SRTs) were compared for: Quiet (target 0 degrees front, no interferer), Front (target and interferer both 0 degrees front), and Right (interferer 90 degrees right, target 0 degrees front). Children had higher SRTs and greater masking than adults. When spatial cues were not available, adults, but not children, were able to use differences in interferer type to separate the target from the interferer. Both children and adults showed SRM. Children, unlike adults, demonstrated large amounts of SRM for a time-reversed speech interferer. In conclusion, masking and SRM vary with the type of interfering sound, and this variation interacts with age; SRM may not depend on the spectral peculiarities of a particular type of voice when the target speech and interfering speech are different sex talkers.

Acoustic Stimulation↗