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Biomedical subjects

T Rahko

Publications and source records attributed to T Rahko.

At least 73 records · Page 4Linked to original sources

Effect of word speed, number of words, and habituation on the discrimination score of synthesized speech.

The audiologic uses of Synte 2, a speech synthetizer converting text into speech, with unlimited word capacity, are described, One hundred persons with normal hearing, who were divided into four equal groups, listened to 150 to 400 words uttered at speeds equal to rates of 50, 60, 70 and 80 words per minute. Groups of words were uttered at 5-sec intervals at 50 dB SL. After 100 words the listeners' discrimination scores rose to over 80%. The highest mean score was 85%. The results were much the same for all the speeds tried. Synthesized speech affords the only means of producing identical, sensitized-speech tests over and over again. Although naturally the original tapes wear out, master tapes made on different occasions keep the test results constant. Synte 2 also provides an aid for the mute. It makes man-machine communication possible in business and industrial use. It serves a useful purpose in speech pathology and phoniatric examinations. A discussion machine is under development.

Adolescent↗

Prevalence of handicapping hearing loss in an aging population.

The mean hearing thresholds of 369 Finnish inhabitants, 65 years, and born in 3 consecutive years on two elected days each year, were studied in high standard measurement conditions. Eighty-nine of these subjects were reexamined 3 years later. They represented a typical partly industrialized white population with a high standard of living. With the criteria for hearing rehabilitation for presbycusis set at a mean hearing threshold of 30 dB or worse at 500 to 1,000 to 2,000 Hz, and/or 50-dB hearing loss at 2,000 Hz, the prevalence of rehabilitation need was 3.2%. Conductive hearing losses were found in 6% of the subjects.

Age Factors↗

SISI test and adaptation. II. Subjects with conductive hearing defects.

The effect of adaptation of the ear on the SISI test was studied at 500 Hz and 2000 Hz in 43 patients with chronic otitis and in 20 patients with otosclerosis. The mean adaptation was slightly over 10 dB, except in the otosclerosis group at 2000 Hz, for which the value was nearly 20 dB after continuous stimulation at 20 dB SL for 3 min. The mean SISI values ranged from 15% to 31% in the preadaptation tests and from 9% to 31% in the postadaptation tests. The scatter of the pre-and postadaptation SISI scores was wide, making statistical treatment of the results difficult. In the total material 22% of the values at 2000 Hz were positive according to Jerger's classification, and 32% were questionable. Adaptation slightly reduced the proportion of positive values, but there were changes towards both higher and lower levels in the cases of chronic otitis, while all the otosclerosis changes were diminutions.

Acoustic Stimulation↗

SISI test and adaptation. III. Subjects with perceptive hearing defects.

The effect of the adaptation of the ear on the SISI test was studied in 60 completely and 18 incompletely recuriting patients and in 5 patients with a verified acoustic neurinoma at 500 and 2000 Hz. The subjective suprathreshold adaptation to a 3 min tone of 20 dB (SL) ranged from 10 dB to over 20 dB, depending on the frequency and type of defect. The pre-adaptation mean SISI values in the recruiting groups ranged from 38 to 51% and the post-adaptation means from 38 to 49%. In retrocochlear lesions only one SISI value was questionable before and after adaptation, the others being 0%. The dispersion of the SISI scores was considerable, a fact that made statistical treatment difficult. Adaptation did not significantly affect the SISI value. It could be ascertained that high SISI values did not reliably distinguish between the hearing defect types, but if the SISI was low the possibility of a retrocochlear lesion should always be borne in mind.

Acoustic Stimulation↗

Sensorineural hearing loss and acute otitis media in children.

Sensorineural hearing of 359 otoscopically and tympanometrically normal 5-year-old children with known otitis-history was studied under ideal conditions. In the subgroups of children with a different number (0, 1-2, 3-7, greater than or equal to 8) of attacks of acute otitis media (AOM) in their history, the mean bone conduction thresholds unregularly varied from 0.1 dB to 7.4 dB, depending on the frequency and the subgroup studied. The proportion of the ears with a bone conduction threshold greater than 10 dB at 0.5, 1, 2 or kHz ranged, also unregularly, from 10.8% to 0.5%, the greatest percentages being found at 0.5 and 1 kHz in the children without a history of AOM. Thus, neither AOM nor its treatment, even if frequently occurring, seem to cause permanent sensorineural hearing loss in children.

Acute Disease↗