Perception of a Spectrally Deprived Speech Signal

It was found that, at a test bandwidth range of 50 Hz, 100% speech intelligibility is retained in naive subjects when, on average, 950 Hz is removed from each subsequent 1000-Hz bandwidth. Thus, speech is 95% redundant with respect to the spectral content. The parameters of the comb filter were chosen from measurements of speech intelligibility in experienced subjects, at which no one subject with normal hearing taking part in the experiment for the first time exhibited 100% intelligibility. Two methods of learning to perceive spectrally deprived speech signals are compared: (1) aurally only and (2) with visual enhancement. In the latter case, speech intelligibility is significantly higher. The possibility of using a spectrally deprived speech signal to develop and assess the efficiency of auditory rehabilitation of implanted patients is discussed.     

Speech intelligibility after partial glossectomy in children with Down's syndrome

Twenty-three children with Down's syndrome, aged between 3.7 and 17.5 years, underwent partial glossectomy for improvement of cosmetic appearance. Improved speech was also expected. Preoperative and postoperative audiotaped samples of spoken words and connected speech on a standardized articulation test were rated by three lay and three expert listeners on a five-point intelligibility scale. Five subjects were eliminated from both tasks and another four from connected-speech testing because of inability to complete the experimental tasks. Statistical analyses of ratings for words in 18 subjects and connected speech in 14 of them revealed no significant difference in acoustic speech intelligibility preoperatively and postoperatively. The findings suggest that a wedge-excision partial glossectomy in children with Down's syndrome does not result in significant improvement in acoustic speech intelligibility; in some patients, however, there may be an aesthetic improvement during speech.     

Perceptual Learning of Interrupted Speech

The intelligibility of periodically interrupted speech improves once the silent gaps are filled with noise bursts. This improvement has been attributed to phonemic restoration, a top-down repair mechanism that helps intelligibility of degraded speech in daily life. Two hypotheses were investigated using perceptual learning of interrupted speech. If different cognitive processes played a role in restoring interrupted speech with and without filler noise, the two forms of speech would be learned at different rates and with different perceived mental effort. If the restoration benefit were an artificial outcome of using the ecologically invalid stimulus of speech with silent gaps, this benefit would diminish with training. Two groups of normal-hearing listeners were trained, one with interrupted sentences with the filler noise, and the other without. Feedback was provided with the auditory playback of the unprocessed and processed sentences, as well as the visual display of the sentence text. Training increased the overall performance significantly, however restoration benefit did not diminish. The increase in intelligibility and the decrease in perceived mental effort were relatively similar between the groups, implying similar cognitive mechanisms for the restoration of the two types of interruptions. Training effects were generalizable, as both groups improved their performance also with the other form of speech than that they were trained with, and retainable. Due to null results and relatively small number of participants (10 per group), further research is needed to more confidently draw conclusions. Nevertheless, training with interrupted speech seems to be effective, stimulating participants to more actively and efficiently use the top-down restoration. This finding further implies the potential of this training approach as a rehabilitative tool for hearing-impaired/elderly populations.     

Speech Misperception: Speaking and Seeing Interfere Differently with Hearing

Speech perception is thought to be linked to speech motor production. This linkage is considered to mediate multimodal aspects of speech perception, such as audio-visual and audio-tactile integration. However, direct coupling between articulatory movement and auditory perception has been little studied. The present study reveals a clear dissociation between the effects of a listener’s own speech action and the effects of viewing another’s speech movements on the perception of auditory phonemes. We assessed the intelligibility of the syllables [pa], [ta], and [ka] when listeners silently and simultaneously articulated syllables that were congruent/incongruent with the syllables they heard. The intelligibility was compared with a condition where the listeners simultaneously watched another’s mouth producing congruent/incongruent syllables, but did not articulate. The intelligibility of [ta] and [ka] were degraded by articulating [ka] and [ta] respectively, which are associated with the same primary articulator (tongue) as the heard syllables. But they were not affected by articulating [pa], which is associated with a different primary articulator (lips) from the heard syllables. In contrast, the intelligibility of [ta] and [ka] was degraded by watching the production of [pa]. These results indicate that the articulatory-induced distortion of speech perception occurs in an articulator-specific manner while visually induced distortion does not. The articulator-specific nature of the auditory-motor interaction in speech perception suggests that speech motor processing directly contributes to our ability to hear speech.     

Cutaneous surgeons cannot predict blood-thinner status by intraoperative visual inspection

Cutaneous surgeons cannot predict blood-thinner status by intraoperative visual inspection. Many surgeons believe they can discern whether a patient is taking an anticoagulant or a platelet inhibitor (blood thinner) by visual inspection of intraoperative oozing. However, there is little objective evidence to support this strongly held belief. The authors' objective was to determine whether visual inspection of intraoperative oozing during cutaneous surgery is accurate in identifying use of blood thinners. Blinded physician evaluators observed intraoperative oozing in 110 patients having cutaneous excisional surgery, rated the amount of oozing, and judged the likelihood that the patient was taking a blood-thinning agent. On the basis of the impressions of the most senior evaluator, 43 patients having used aspirin in the past 14 days or warfarin or vitamin E in the past 2 days, seven were judged as definitely or probably taking blood-thinning agents (sensitivity, 16.3 percent; 95 percent confidence interval, 6.8 to 30.7 percent). Of 67 patients who did not report recent use of a blood-thinning agent, just 11 were judged as definitely or probably taking blood-thinning agents (false-positive rate, 16.4 percent; 95 percent confidence interval, 8.5 to 27.5 percent). The level of training of the physicians doing the judging did not affect diagnostic sensitivity. Only 10 of the 110 patients (9.1 percent) were assessed as exhibiting excessive oozing, and of those, only four (40 percent) were actually taking a blood thinner. Results were similar when only patients who were taking aspirin or warfarin were analyzed. Thus, contrary to a commonly and strongly held belief, visual inspection of intraoperative oozing during cutaneous excisional surgery correlates poorly with blood-thinner use by patients. The data add further evidence that use of blood thinners does not have an objectively measurable adverse effect during cutaneous surgery.     

Collaboration of a dentist and speech-language pathologist in the rehabilitation of a stroke patient with dysarthria: a case study

Objective: To elucidate the effectiveness of the collaboration of a dentist and speech‐language pathologist (SLP) in the rehabilitation of a stroke patient with dysarthria. Design: A clinical case report treated in the rehabilitation hospital and dental surgery. Subject: A 71‐year‐old Japanese man who was admitted to the rehabilitation hospital for speech rehabilitation 2 years and 5 months after a stroke. Methods: Provision of prosthesis (palatal lift prosthesis + palatal augmentation prosthesis) for improving velopharyngeal incompetence (VPI) and articulation by dentist, and speech behavioural management by SLP including self‐monitoring and bio‐feedback training using the See‐Scape. Results: Speech behavioural management proved useful for promoting improvement in speech intelligibility to a functionally sufficient level after improving VPI by prosthesis. Conclusion: The collaborative efforts of the dentist and SLP in the rehabilitation of post‐stroke patients with velopharyngeal incompetence should be encouraged.     

Predictors of velopharyngeal insufficiency in cleft palate orthognathic surgery

The purpose of this study was to appraise the value of preoperative speech assessments, nasopharyngoscopy, and surgical models as predictors of velopharyngeal deterioration after a Le Fort I maxillary advancement in cleft patients. This retrospective study involved a series of 26 cleft patients (16 unilateral complete and nine bilateral complete cleft lips and palates, and one isolated complete cleft palate) who had Le Fort I maxillary advancements between March 1, 1993, and February 7, 1996. The 13 male patients and 13 female patients ranged in age from 15.3 to 46 years (mean age, 19.5 years). Four of these patients had previously undergone pharyngeal flap surgery. Eleven patients had palatal fistulas and one had a bifid uvula that was repaired at the time of orthognathic surgery. Patients with perceived hypernasal speech preoperatively all had hypernasality after advancement (nine of nine). Velopharyngeal insufficiency was observed in two of the 16 whose resonance preoperatively was within normal limits. Speech assessment, therefore, predicted accurately the postoperative status in 23 of 26 patients. Twelve patients had preoperative nasopharyngoscopy that indicated a high risk for velopharyngeal insufficiency (borderline or inadequate closure). Nine of these patients had postoperative velopharyngeal insufficiency. Two of the 14 patients not judged at risk by nasopharyngoscopy developed velopharyngeal insufficiency. Therefore, 21 of the 26 patients were accurately predicted by nasopharyngoscopy. Scoping detected borderline velopharyngeal insufficiency in one patient who was not detected by speech alone. The combined predictive value of speech and scope identified all but one patient who would develop postoperative velopharyngeal insufficiency. The degree of anteroposterior movement determined from surgical models was not predictive of the outcome. Patients with hypernasal speech preoperatively continue to have hypernasal speech after Le Fort I advancement. Preoperative perceptual speech assessment by specially trained speech-language pathologists is an excellent test for predicting postoperative velopharyngeal insufficiency status. Nasopharyngoscopy is an invasive and resource-dependent test that should be assessed with respect to cost effectiveness. In this series, only one patient's risk was more accurately predicted using nasopharyngoscopy than by speech assessment alone.     

Let's All Speak Together! Exploring the Masking Effects of Various Languages on Spoken Word Identification in Multi-Linguistic Babble

This study aimed to characterize the linguistic interference that occurs during speech-in-speech comprehension by combining offline and online measures, which included an intelligibility task (at a −5 dB Signal-to-Noise Ratio) and 2 lexical decision tasks (at a −5 dB and 0 dB SNR) that were performed with French spoken target words. In these 3 experiments we always compared the masking effects of speech backgrounds (i.e., 4-talker babble) that were produced in the same language as the target language (i.e., French) or in unknown foreign languages (i.e., Irish and Italian) to the masking effects of corresponding non-speech backgrounds (i.e., speech-derived fluctuating noise). The fluctuating noise contained similar spectro-temporal information as babble but lacked linguistic information. At −5 dB SNR, both tasks revealed significantly divergent results between the unknown languages (i.e., Irish and Italian) with Italian and French hindering French target word identification to a similar extent, whereas Irish led to significantly better performances on these tasks. By comparing the performances obtained with speech and fluctuating noise backgrounds, we were able to evaluate the effect of each language. The intelligibility task showed a significant difference between babble and fluctuating noise for French, Irish and Italian, suggesting acoustic and linguistic effects for each language. However, the lexical decision task, which reduces the effect of post-lexical interference, appeared to be more accurate, as it only revealed a linguistic effect for French. Thus, although French and Italian had equivalent masking effects on French word identification, the nature of their interference was different. This finding suggests that the differences observed between the masking effects of Italian and Irish can be explained at an acoustic level but not at a linguistic level.     

Development of articulation before delayed hard-palate closure in children with cleft palate: a cross-sectional study

The development of articulation before surgical closure of the hard palate was compared in 75 preschool children with cleft lip and palate and 40 preschool children born without clefts. The children were aged 2 years to 5 years 11 months. The patients had significantly poorer articulation skills than the controls at each age level. Substitutions were the most frequent error, and they did not decrease with age in the patients. Fistula size and a history of speech therapy were significant factors in the articulation error scores only in 5-year-olds. No advantage in articulation proficiency was found for those who had worn a prosthesis to occlude the hard-palate defect.     

Effects of castration age,protein level and lysine/methionine ratio in the diet on colour,lipid oxidation and meat acceptability of intensively reared Friesian steers

A total of 64 intensively reared Friesian steers were used in a 2×2×2 design to study the effects of age of castration (15 days old v. 5 months old), dietary protein level (14.6% v. 16.8%; DM basis) and lysine/methionine (lys/met) ratio (3.0 v. 3.4) on meat quality. The lys/met ratio of 3.0 was reached with supplementation of protected methionine. Animals were slaughtered at a live weight of 443.5±26.2 kg at around 12 months of age. Colour and lipid oxidation were measured in the longissimus thoracis muscle throughout the 14 days of display under modified atmospheric and commercial display conditions. A panel of 17 consumers assessed daily the visual acceptability of the meat on display. A consumer acceptability eating test was also performed with 120 consumers in meat aged for 7 days under vacuum conditions. Lipid oxidation was not influenced by castration age and the protein level in the diet. Castration age did not affect meat colour, but meat from the low protein level diet and the low lys/met ratio showed higher redness (a*) from 3 days of display onwards. Nevertheless, from 6 days onwards, consumer visual acceptability was below the level of acceptance in all treatments, and even from 5 days onwards in those animals that underwent early castration and were fed either a high protein diet or a combination diet low in protein content and high in lys/met ratio. The best accepted treatments throughout the display period were those from late castrated animals fed a low protein diet, probably related to other visual aspects. However, the best accepted meat after consumption was that from late castrated animals fed high protein and high lys/met. The addition of protected methionine to reach lys/met levels of 3.0 did not improve beef acceptability, with the high protein diet being preferred by consumers in terms of palatability in late castrated animals.     

Levator muscle reconstruction: resulting velopharyngeal competence--a preliminary report

The purpose of this study was to evaluate a levator muscle reconstruction procedure on the basis of resulting velopharyngeal competence. Ages of the patients at time of surgery ranged from 5 months to 7 years. The patients were reevaluated postoperatively. If the patients were judged to have normal nasality and no nasal emission, the procedure was considered to have yielded a satisfactory result. If hypernasality and nasal emission resulted, the patients were examined utilizing nasoendoscopy and/or videofluoroscopy. If velopharyngeal incompetence was confirmed, the operative procedure was judged to be successful. Results showed that 60 percent success was achieved. The age range which yielded the best results (73 percent satisfactory) was 37 to 60 months. The data also revealed that the more severe the cleft, the less likely this operative procedure is to produce satisfactory results. The authors recommend continued evaluation of this procedure, preferably utilizing prospective studies.     

Timing of Surgical Intervention with Cochlear Implant in Patients with Large Vestibular Aqueduct Syndrome

Objectives

(1) To report the speech perception and intelligibility results of Mandarin-speaking patients with large vestibular aqueduct syndrome (LVAS) after cochlear implantation (CI); (2) to compare their performance with a group of CI users without LVAS; (3) to understand the effects of age at implantation and duration of implant use on the CI outcomes. The obtained data may be used to guide decisions about CI candidacy and surgical timing.

Methods

Forty-two patients with LVAS participating in this study were divided into two groups: the early group received CI before 5 years of age and the late group after 5. Open-set speech perception tests (on Mandarin tones, words and sentences) were administered one year after implantation and at the most recent follow-up visit. Categories of auditory perception (CAP) and Speech Intelligibility Rating (SIR) scale scores were also obtained.

Results

The patients with LVAS with more than 5 years of implant use (18 cases) achieved a mean score higher than 80% on the most recent speech perception tests and reached the highest level on the CAP/SIR scales. The early group developed speech perception and intelligibility steadily over time, while the late group had a rapid improvement during the first year after implantation. The two groups, regardless of their age at implantation, reached a similar performance level at the most recent follow-up visit.

Conclusion

High levels of speech performance are reached after 5 years of implant use in patients with LVAS. These patients do not necessarily need to wait until their hearing thresholds are higher than 90 dB HL or PB word score lower than 40% to receive CI. They can do it “earlier” when their speech perception and/or speech intelligibility do not reach the performance level suggested in this study.     

Comfortable Loudness Level and Phrase Intelligibility of Spectrally Deprived Speech

It is known from the literature that (1) sounds with complex spectral composition are assessed by summing the partial outputs of the spectral channels; (2) electrical stimuli used in cochlear implant systems bring about the perception of a frequency band; and (3) removal of different parts of the auditory spectrum significantly affects phrase intelligibility. The level of acoustic pressure (AP) at a comfortable loudness level and the phrase intelligibility after comb filtering of a speech signal were measured in normally hearing subjects. Using a software program for spectral transformation of the speech signal, the phrase spectrum was divided into frequency bands of various width and only the bands with odd numbers were summed. In three series, the width of odd bands was 50, 100, or 150 Hz and the width of even bands was varied. The filter period was equal to the sum of the even and odd bands. With the same period, the acoustic pressure of the output signal should be increased to reach the comfortable loudness level of a speech signal passed via the comb filter; the narrower the width of the test bands, the higher the AP increase. With the same width of the test band, the acoustic pressure of the output signal should be increased to reach the comfortable loudness level; the greater the filter period, the higher the increase should be. The speech signal redundancy with respect to its spectral content can be equal to or even exceed 97.5%.     

Skeletal stability after Le Fort I maxillary advancement in patients with unilateral cleft lip and palate

Outcomes in 30 adults and adolescents judged skeletally mature who had unilateral cleft lip and palate and underwent Le Fort I advancement were investigated to determine amount and timing of relapse, correlation between advancement and relapse, effect of performing multiple jaw procedures, effect of different types of bone grafts, effect of pharyngoplasty in place at the time of osteotomy, and effectiveness of various methods of internal fixation. Tracings of preoperative and serial postoperative lateral cephalograms were digitized to calculate horizontal and vertical maxillary changes. No significant differences in outcome was seen between patients who had maxillary surgery alone and those who had operations on both jaws, nor did the outcome vary significantly with the type of autogenous bone graft used or the segmentalization of the Le Fort osteotomy. Mean "effective" advancement was greater immediately and 2 years after surgery in those patients who did not have a pharyngoplasty in place before the operation. Advancement also was greater immediately and after 2 years in the miniplate fixation group than in patients with direct-wire fixation. Mean downward (vertical) displacement was 2.6 mm with a relapse of 1.4 mm after 2 years. Amounts of relapse and of advancement or displacement did not correlate significantly.     

Functional Connectivity between Face-Movement and Speech-Intelligibility Areas during Auditory-Only Speech Perception

It has been proposed that internal simulation of the talking face of visually-known speakers facilitates auditory speech recognition. One prediction of this view is that brain areas involved in auditory-only speech comprehension interact with visual face-movement sensitive areas, even under auditory-only listening conditions. Here, we test this hypothesis using connectivity analyses of functional magnetic resonance imaging (fMRI) data. Participants (17 normal participants, 17 developmental prosopagnosics) first learned six speakers via brief voice-face or voice-occupation training (<2 min/speaker). This was followed by an auditory-only speech recognition task and a control task (voice recognition) involving the learned speakers’ voices in the MRI scanner. As hypothesized, we found that, during speech recognition, familiarity with the speaker’s face increased the functional connectivity between the face-movement sensitive posterior superior temporal sulcus (STS) and an anterior STS region that supports auditory speech intelligibility. There was no difference between normal participants and prosopagnosics. This was expected because previous findings have shown that both groups use the face-movement sensitive STS to optimize auditory-only speech comprehension. Overall, the present findings indicate that learned visual information is integrated into the analysis of auditory-only speech and that this integration results from the interaction of task-relevant face-movement and auditory speech-sensitive areas.     

Prolonged conservative care versus early surgery in patients with sciatica caused by lumbar disc herniation: two year results of a randomised controlled trial

Objectives To evaluate the effects of early lumbar disc surgery compared with prolonged conservative care for patients with sciatica over two years of follow-up.Design Randomised controlled trial.Setting Nine Dutch hospitals.Participants 283 patients with 6-12 weeks of sciatica.Interventions Early surgery or an intended six months of continued conservative treatment, with delayed surgery if needed.Main outcome measures Scores from Roland disability questionnaire for sciatica, visual analogue scale for leg pain, and Likert self rating scale of global perceived recovery.Results Of the 141 patients assigned to undergo early surgery, 125 (89%) underwent microdiscectomy. Of the 142 patients assigned to conservative treatment, 62 (44%) eventually required surgery, seven doing so in the second year of follow-up. There was no significant overall difference between treatment arms in disability scores during the first two years (P=0.25). Improvement in leg pain was faster for patients randomised to early surgery, with a significant difference between “areas under the curves” over two years (P=0.05). This short term benefit of early surgery was no longer significant by six months and continued to narrow between six months and 24 months. Patient satisfaction decreased slightly between one and two years for both groups. At two years 20% of all patients reported an unsatisfactory outcome.Conclusions Early surgery achieved more rapid relief of sciatica than conservative care, but outcomes were similar by one year and these did not change during the second year.Trial Registry ISRCT No 26872154.     

Transient but Significant Visual Field Defects after Robot-Assisted Laparoscopic Radical Prostatectomy in Deep Trendelenburg Position

Background

Robot-assisted laparoscopic radical prostatectomy (RALP) is a minimally invasive surgical procedure for prostate cancer. During RALP, the patient must be in a steep Trendelenburg (head-down) position, which leads to a significant increase in intraocular pressure (IOP). The association of RALP with visual field sensitivity, however, has not been prospectively studied. The purpose of this study was to evaluate prospectively the visual field, retinal nerve fiber layer (RNFL) thickness, and optic disc morphology in 50 normal eyes of 25 male patients that underwent RALP.

Methods

The subjects were 25 males among 33 consecutive patients who underwent uneventful RALP under general anesthesia in our hospital. Visual field tests using the Humphrey visual field analyzer 30-2 SITA-standard program were performed before, 7 days after, and 1-3 months after RALP. IOP was measured before, during, and after RALP; and ophthalmologic examinations, including slit-lamp, fundus examination, and optical coherence tomography (OCT), were scheduled before and 7 days after surgery.

Results

IOP was significantly increased during RALP up to 29.4 mmHg (P<0.01). Postoperative local visual field defects were detected in 7 eyes of 7 subjects dominantly in the lower hemifield without abnormal findings in the optic nerve head or retina, and the visual field recovered to normal within 3 months after surgery. General factors associated with RALP, IOP, RNFL thickness, or optic disc parameters did not differ significantly between eyes with and without postoperative visual field defects, and parameters of OCT measurements were not altered after surgery.

Conclusion

Transient but significant unilateral visual field defects were found in 28% of the subjects examined. The probable cause are the increased IOP and altered perfusion during surgery and ophthalmologic examinations are therefore suggested before and after RALP.     

Motherese by Eye and Ear: Infants Perceive Visual Prosody in Point-Line Displays of Talking Heads

Infant-directed (ID) speech provides exaggerated auditory and visual prosodic cues. Here we investigated if infants were sensitive to the match between the auditory and visual correlates of ID speech prosody. We presented 8-month-old infants with two silent line-joined point-light displays of faces speaking different ID sentences, and a single vocal-only sentence matched to one of the displays. Infants looked longer to the matched than mismatched visual signal when full-spectrum speech was presented; and when the vocal signals contained speech low-pass filtered at 400 Hz. When the visual display was separated into rigid (head only) and non-rigid (face only) motion, the infants looked longer to the visual match in the rigid condition; and to the visual mismatch in the non-rigid condition. Overall, the results suggest 8-month-olds can extract information about the prosodic structure of speech from voice and head kinematics, and are sensitive to their match; and that they are less sensitive to the match between lip and voice information in connected speech.     

Unconscious context control of visual perception of simple stimuli: A study using evoked potentials

The effect of nonsemantic context on the perception of simple nonverbal visual stimuli has been studied in ten healthy volunteers by the event-related potential (ERP) method. The nonsemantic context was specified by the formation of a memory trace of a test visual stimulus via its repeated presentation without any instruction except gaze fixation. Then, this stimulus randomly alternated with control stimuli that did not form memory traces before their presentation. It has been found that an ERP in the interval 260–340 ms after presentation of a simple nonverbal stimulus significantly differs from the control ERPs. The results suggest that some stages of the processing of visual stimuli may be modified by nonsemantic context.     

The Effect of Automatic Gain Control Structure and Release Time on Cochlear Implant Speech Intelligibility

Nucleus cochlear implant systems incorporate a fast-acting front-end automatic gain control (AGC), sometimes called a compression limiter. The objective of the present study was to determine the effect of replacing the front-end compression limiter with a newly proposed envelope profile limiter. A secondary objective was to investigate the effect of AGC speed on cochlear implant speech intelligibility. The envelope profile limiter was located after the filter bank and reduced the gain when the largest of the filter bank envelopes exceeded the compression threshold. The compression threshold was set equal to the saturation level of the loudness growth function (i.e. the envelope level that mapped to the maximum comfortable current level), ensuring that no envelope clipping occurred. To preserve the spectral profile, the same gain was applied to all channels. Experiment 1 compared sentence recognition with the front-end limiter and with the envelope profile limiter, each with two release times (75 and 625 ms). Six implant recipients were tested in quiet and in four-talker babble noise, at a high presentation level of 89 dB SPL. Overall, release time had a larger effect than the AGC type. With both AGC types, speech intelligibility was lower for the 75 ms release time than for the 625 ms release time. With the shorter release time, the envelope profile limiter provided higher group mean scores than the front-end limiter in quiet, but there was no significant difference in noise. Experiment 2 measured sentence recognition in noise as a function of presentation level, from 55 to 89 dB SPL. The envelope profile limiter with 625 ms release time yielded better scores than the front-end limiter with 75 ms release time. A take-home study showed no clear pattern of preferences. It is concluded that the envelope profile limiter is a feasible alternative to a front-end compression limiter.