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Human ultrasonic speech perception
Abstracts
Abstracts ELLIOT ABEMAYOR, MD,
Better Speech Recognition With Cochlear Implants. BW Wilson, CC Finley, 1991; 352:236-238
DT Lawson,
PHD, EDITOR
Pathophysiology of Upper Airway Closure During Sleep. ST Kuna, G Sant’Ambrogio. JAMA 1991;
et al. Nature
266:1384-1389
Cochlear implant systems are increasingly used to rehabilitate patients with postlingual deafness. High levels of speech recognition have been achieved with multielectrode implants. This investigation compares two types of cochlear implants: one using a standard compressed analogue processor in which analogue waveforms are simultaneously presented to all electrodes and one using a continuous interleaved sample strategy that presents brief pulses to each electrode in a nonoverlapping sequence. Seven experienced implant users were selected for this study. The new strategy produced large improvements in the scores of speech reception tests for all subjects, The continuous interleaves sampling strategy establishes new levels of performance for cochlear implants. The factors that contributed to the high performance may include reduction in channel interactions, use of multiple channels, and preservation of amplitude cues. This is an important study for physicians working with cochlear implants in that it uses a new mode of presenting speech. Aside from improving speech recognition, this study provides further insight into the minimal cues necessary for speech understanding.
In quiet breathing, the upper airway normally remains patent. Patients with obstructive sleep apnea (OSA) have repetitive periods of upper airway closure during sleep. Such closure occurs at various sites within the pharynx. The pharynx consists of the nasopharynx, oropharynx, and hypopharynx. This article is a nice review of the pathophysiology of upper airway closure during sleep. The authors point out that in OSA patients, upper airway obstruction in the pharynx usually involves approximately a l-cm length of the airway. This may change during apnea. Following the onset of sleep, there is a decrease in muscle tension with pharyngeal narrowing and closure followed by intermittent arousal with sudden opening of the pharynx. Since OSA can be morbid and has an appreciable associated mortality, the economic consequences are farreaching. The authors consider tracheostomy the most effective surgical treatment for OSA. However, this is seldom used as first-line treatment. Uvulopalatopharyngoplasty and continuous positive airway pressure are also effective in treating OSA. Many significant advances in the treatment of patients with OSA have been reported over the past decade. This is a complete overview for any head and neck surgeon who treats patients with this disorder.
Human Ultrasonic Speech Perception. ML Lenhardt, R Skellett,
P Wang, et al. Science
The Interferons: Mechanisms of Actions and Clinical Applications. S Baron, SK Tyring, WR Fleischmann,
1991; 253:82-85
Human air conduction hearing is believed to be no higher than 24,000 Hz. However ultrasonic bone conduction hearing in humans has been demonstrated. Bone-conducted ultrasonic hearing has been found capable of supporting frequency discrimination and speech detection in normal, older hearing impaired, and profoundly deaf human subjects. This investigation examined the feasibility of presenting speech in the ultrasonic range to such patients. It was found that a neural substrate exists that is capable of uncoding speech signals when these signals are modulated into ultrasonic frequencies. This was true in normal hearing individuals as well as in those with compromised auditory function. Although the specific neural substrates were not examined, it is possible that the transmission of ultrasonic frequencies was by bone conduction. Another possibility is that ultrasonic reception lies in the saccule, an otolithic organ that responds to acceleration and gravity. This organ may also be responsible for the transduction of sound after cochlear destruction. The results presented suggest that in hearing impaired and profoundly deaf subjects, bone-conducted ultrasonic stimulation may provide an alternative therapeutic approach for the rehabilitation of hearing loss.
et al. JAMA 1991; 266:1375-1383 The interferons (IFNs) are one of the body’s natural defensive responses to malignant entities such as tumors, microbes, and viruses. Following exposure to an agent, IFN proteins are produced that induce an appropriate response. Currently, there are several approved indications for IFNs, including some leukemias, Kaposi’s sarcoma, and non-A and non-B viral hepatitis. Promising clinical results have also been reported for basal cell carcinoma, cutaneous squamous cell carcinoma, hepatitis B, and laryngeal papillomas. The mechanism of action for the IFNs has not been fully elucidated. With respect to tumors, IFNs exert antiproliferative effects by increasing the cell multiplication cycle. A direct antitumor effect may also be mediated by modulation of host leukocyte function in immune responses. Of particular relevance to the head and neck surgeon is the fact that laryngeal papillomas can be treated with IFN-alpha; however, one drawback is the need for continuous treatment. Future uses for the IFNs may include infusion as front-line agents for the treatment of solid tumors. This is a critical, concise review article on the use of IFNs in clinical medicine today.
302
Abstracts ELLIOT ABEMAYOR, MD,
Better Speech Recognition With Cochlear Implants. BW Wilson, CC Finley, 1991; 352:236-238
DT Lawson,
PHD, EDITOR
Pathophysiology of Upper Airway Closure During Sleep. ST Kuna, G Sant’Ambrogio. JAMA 1991;
et al. Nature
266:1384-1389
Cochlear implant systems are increasingly used to rehabilitate patients with postlingual deafness. High levels of speech recognition have been achieved with multielectrode implants. This investigation compares two types of cochlear implants: one using a standard compressed analogue processor in which analogue waveforms are simultaneously presented to all electrodes and one using a continuous interleaved sample strategy that presents brief pulses to each electrode in a nonoverlapping sequence. Seven experienced implant users were selected for this study. The new strategy produced large improvements in the scores of speech reception tests for all subjects, The continuous interleaves sampling strategy establishes new levels of performance for cochlear implants. The factors that contributed to the high performance may include reduction in channel interactions, use of multiple channels, and preservation of amplitude cues. This is an important study for physicians working with cochlear implants in that it uses a new mode of presenting speech. Aside from improving speech recognition, this study provides further insight into the minimal cues necessary for speech understanding.
In quiet breathing, the upper airway normally remains patent. Patients with obstructive sleep apnea (OSA) have repetitive periods of upper airway closure during sleep. Such closure occurs at various sites within the pharynx. The pharynx consists of the nasopharynx, oropharynx, and hypopharynx. This article is a nice review of the pathophysiology of upper airway closure during sleep. The authors point out that in OSA patients, upper airway obstruction in the pharynx usually involves approximately a l-cm length of the airway. This may change during apnea. Following the onset of sleep, there is a decrease in muscle tension with pharyngeal narrowing and closure followed by intermittent arousal with sudden opening of the pharynx. Since OSA can be morbid and has an appreciable associated mortality, the economic consequences are farreaching. The authors consider tracheostomy the most effective surgical treatment for OSA. However, this is seldom used as first-line treatment. Uvulopalatopharyngoplasty and continuous positive airway pressure are also effective in treating OSA. Many significant advances in the treatment of patients with OSA have been reported over the past decade. This is a complete overview for any head and neck surgeon who treats patients with this disorder.
Human Ultrasonic Speech Perception. ML Lenhardt, R Skellett,
P Wang, et al. Science
The Interferons: Mechanisms of Actions and Clinical Applications. S Baron, SK Tyring, WR Fleischmann,
1991; 253:82-85
Human air conduction hearing is believed to be no higher than 24,000 Hz. However ultrasonic bone conduction hearing in humans has been demonstrated. Bone-conducted ultrasonic hearing has been found capable of supporting frequency discrimination and speech detection in normal, older hearing impaired, and profoundly deaf human subjects. This investigation examined the feasibility of presenting speech in the ultrasonic range to such patients. It was found that a neural substrate exists that is capable of uncoding speech signals when these signals are modulated into ultrasonic frequencies. This was true in normal hearing individuals as well as in those with compromised auditory function. Although the specific neural substrates were not examined, it is possible that the transmission of ultrasonic frequencies was by bone conduction. Another possibility is that ultrasonic reception lies in the saccule, an otolithic organ that responds to acceleration and gravity. This organ may also be responsible for the transduction of sound after cochlear destruction. The results presented suggest that in hearing impaired and profoundly deaf subjects, bone-conducted ultrasonic stimulation may provide an alternative therapeutic approach for the rehabilitation of hearing loss.
et al. JAMA 1991; 266:1375-1383 The interferons (IFNs) are one of the body’s natural defensive responses to malignant entities such as tumors, microbes, and viruses. Following exposure to an agent, IFN proteins are produced that induce an appropriate response. Currently, there are several approved indications for IFNs, including some leukemias, Kaposi’s sarcoma, and non-A and non-B viral hepatitis. Promising clinical results have also been reported for basal cell carcinoma, cutaneous squamous cell carcinoma, hepatitis B, and laryngeal papillomas. The mechanism of action for the IFNs has not been fully elucidated. With respect to tumors, IFNs exert antiproliferative effects by increasing the cell multiplication cycle. A direct antitumor effect may also be mediated by modulation of host leukocyte function in immune responses. Of particular relevance to the head and neck surgeon is the fact that laryngeal papillomas can be treated with IFN-alpha; however, one drawback is the need for continuous treatment. Future uses for the IFNs may include infusion as front-line agents for the treatment of solid tumors. This is a critical, concise review article on the use of IFNs in clinical medicine today.
302