Effects of listener age and native language on perception of accented and unaccented sentences.

Degradations to auditory input have deleterious effects on speech recognition performance, especially by older listeners. Alterations to timing information in speech, such as occurs in rapid or foreign-accented speech, can be particularly difficult for older people to resolve. It is currently unclear how prior language experience modulates performance with temporally altered sentence-length speech utterances. The principal hypothesis is that prior experience with a foreign language affords an advantage for recognition of accented English when the talker and listener share the same native language, which may minimize age-related differences in performance with temporally altered speech. A secondary hypothesis is that native language experience with a syllable-timed language (Spanish) is advantageous for recognizing rapid English speech. Native speakers of English and Spanish completed speech recognition tasks with both accented and unaccented English sentences presented in various degrees of time compression (TC). Native English listeners showed higher or equivalent recognition of accented and unaccented English speech compared to native Spanish listeners in all TC conditions. Additionally, significant effects of aging were seen for native Spanish listeners on all tasks. Overall, the results did not support the hypotheses for a benefit of shared language experience for non-native speakers of English, particularly older native Spanish listeners.

Recognition of asynchronous auditory-visual speech by younger and older listeners: A preliminary study.

This study examined the effects of age and hearing loss on recognition of speech presented when the auditory and visual speech information was misaligned in time (i.e., asynchronous). Prior research suggests that older listeners are less sensitive than younger listeners in detecting the presence of asynchronous speech for auditory-lead conditions, but recognition of speech in auditory-lead conditions has not yet been examined. Recognition performance was assessed for sentences and words presented in the auditory-visual modalities with varying degrees of auditory lead and lag. Detection of auditory-visual asynchrony for sentences was assessed to verify that listeners detected these asynchronies. The listeners were younger and older normal-hearing adults and older hearing-impaired adults. Older listeners (regardless of hearing status) exhibited a significant decline in performance in auditory-lead conditions relative to visual lead, unlike younger listeners whose recognition performance was relatively stable across asynchronies. Recognition performance was not correlated with asynchrony detection. However, one of the two cognitive measures assessed, processing speed, was identified in multiple regression analyses as contributing significantly to the variance in auditory-visual speech recognition scores. The findings indicate that, particularly in auditory-lead conditions, listener age has an impact on the ability to recognize asynchronous auditory-visual speech signals.

[Identification of unknown cadavers--multidisciplinary approach].

The comparison of fingerprints, dentition, genetic profile, imaging data and anthropological characteristics constitute the scientific basis for identification of unknown cadavers. The complexity of the identification process stems from a variety of factors such as the circumstances surrounding the death, the preservation state of the cadaver, availability of identification data and their quality, which affect the feasibility of the identification. This article reviews the most common identification techniques, the various sources of data accessible to the forensic scientist and the strategic decisions through which the unidentified body and the missing person are integrated.

Effects of Listener Age and Native Language Experience on Recognition of Accented and Unaccented English Words.

Purpose Older native speakers of English have difficulty in understanding Spanish-accented English compared to younger native English speakers. However, it is unclear if this age effect would be observed among native speakers of Spanish. The current study investigates the effects of age and native language experience with Spanish on the ability to recognize words spoken in English by Spanish-accented and unaccented talkers. Method English monosyllabic words, recorded by native speakers of English and Spanish, were presented to 4 groups of listeners with normal hearing: younger native Spanish listeners ( n = 15), older native Spanish listeners ( n = 16), younger native English listeners ( n = 15), and older native English listeners ( n = 15). Speech recognition accuracy was assessed for the unaccented and accented words in both quiet and noise. Results In all conditions, the native English listeners performed better than the native Spanish listeners. More specifically, the native speakers of Spanish consistently recognized accented English less accurately than the native speakers of English, demonstrating no advantage of shared native language experience between nonnative listeners and accented talkers. Older listeners in the native Spanish language group also performed less accurately than their younger counterparts, for English words spoken by both unaccented and accented talkers. Finally, whereas listeners who were native speakers of English showed marked declines in recognition of Spanish-accented English relative to unaccented English, listeners who were native speakers of Spanish (both younger and older) showed less decline. Conclusions The general pattern of results suggests that both native language experience in a language other than English and age limit the ability to recognize Spanish-accented English. The implication of the overall findings is that older nonnative listeners will have considerable difficulty in understanding English, regardless of the talker's accent, in both clinical and everyday listening situations.

The medico-legal investigation of the El Aqsah Intifada.

BACKGROUND: The majority (n = 445) of the Israeli and Palestinian fatal victims of the El Aqsah Intifada was examined at the National Center of Forensic Medicine in Tel Aviv. Analysis of the trauma sustained and the anthropologic profile of both the victims and the perpetrators elucidates the trends and contrasts them with the phenomenon in the past. OBJECTIVES: The purpose of the forensic investigation of mass casualty incidents is manifold: establishing the minimal number of individuals involved, identifying the victims and perpetrators, collecting material evidence, and determining the modus operandi. METHODS: The postmortem examination includes external description of the bodies and their injuries, photo-documentation, and sampling of tissues. Radiography, dental examination, and a ten-print card of each cadaver are also recorded. RESULTS: The modus operandi of the current Intifada is somewhat different from that of the previous wave of terrorism and includes more road shootings and vehicular terrorism. In addition, three suicide bombers who detonated explosive devices within crowded areas were young women, and the age of the perpetrators has increased from up to 35 years to individuals as old as 47, thus greatly enlarging the potential number of suicide terrorists. Virologic and biologic tests have been introduced to examine the tissues of the suicide bombers since they are possible sources of contagion to the wounded victims. CONCLUSION: The results of the medico-legal investigation of victims and perpetrators of terrorism enable us to establish the modus operandi and the profile of potential perpetrators, which can help in the prevention of similar attacks. Documentation of the different types of injuries in fatal victims of explosion and shooting contributes to improving the awareness of the medical staff treating the wounded of similar attacks. Further investigation into the reliability of virologic and biologic tests conducted on postmortem tissue is recommended.

The forensic expert witness--an issue of competency.

Scientists submitting expert opinions within the legal system are expected to be knowledgeable in the forensic aspects of their particular science, as well as to be ethical and unbiased. Scientists are seldom able to decline a request to provide an expert opinion in their field, even when their forensic expertise is minimal. The competence of scientists providing expert opinions in forensic cases is reviewed here. Three examples of the perils of uninformed "expertise" in forensic biology, medicine and anthropology are presented.