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PubMed1997

[Speech audiometry with logatomes].

BACKGROUND: Logatomes are nonsense syllables used for analyzing the confusion of phonemes by hearing impaired listeners. They can provide a precise differentiation of phonemic confusions which may be useful in the exact adjustment of programmable hearing aids. METHODS: In this study, two lists of logatomes with 108 three-sound combinations with a structure of consonant-vowel-consonant (c-v-c) and vowel-consonant-vowel (v-c-v) were recorded on a compact disk. Twenty normally hearing adults and 28 patients with a sensorineural hearing loss were tested at a comfortable listening level of about 25 +/- 5 dB above the mean audiometric thresholds at 0,5. 1,0 and 2,0 kHz. An index of reduction of speech perception was calculated. RESULTS: A significant relationship between reduction of logatome perception and pure-tone audiometric thresholds at 1,2,3, and 4 kHz was demonstrated. Moreover, it was possible to distinguish between different groups of hearing impairment. CONCLUSIONS: The logatome test helps to analyze specific effects that hearing loss can have on the recognition of acoustic speech signals. The logatome test may become a valuable addition to speech audiometric tests with further standardization.

Adult↗

PubMed1976

Relation between Paramylum Content and the Length of the Lag Period of Chlorophyll Synthesis during Greening of Dark-grown Euglena gracilis.

Euglena cells, strains Z and bacillaris, were grown in the dark under various nutritional deficiencies. After 3 days of nondivision, cells were transferred to the light, and the following parameters were measured: the paramylum content at the time of illumination (zero time), the rate of paramylum consumption during the first 10 hours of greening, and the length of the lag phase of chlorophyll synthesis. Similar results were obtained with both strains and can be summarized as follows. (a) The use of various nutritional deficiencies allows the control, to a certain extent, of the amount of paramylum present at zero time. (b) The rate of paramylum consumption is proportional to the cellular paramylum content for values in excess of 50 picograms/cell. (c) The length of the lag phase increases rapidly when the cellular content of paramylum decreases below 50 picograms. This period can be greatly diminished by the addition of an exogenous organíc carbon source. (d) The amount of paramylum (rate of paramylum consumption x length of lag phase) consumed during the lag phase is around 5 to 10 picograms/cell for cells which contain less than 50 picograms of paramylum/cell. It increases when the cellular paramylum content increases, this increment being more rapid for bacillaris than for Z cells.

Journal Article↗