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Biomedical subjects

F N Martin

Publications and source records attributed to F N Martin.

At least 19 recordsLinked to original sources
PubMed1994

Sound pressure in the external auditory canal during bone-conduction testing.

Sound pressure levels (SPLs) were measured in the external auditory canals (EACs) of 16 subjects with normal hearing and normal middle ear immittance. SPLs were the result of bone-conduction (BC) stimulation at 500, 1000, 2000, and 4000 Hz, with the oscillator placed either on the forehead or on the mastoid process. At 1000, 2000, and 4000 Hz, significantly higher SPLs were measured when the head was stimulated from the mastoid than from the forehead. When SPLs were compared between right and left EACs, forehead placement of the oscillator produced no interaural differences, while mastoid placement resulted in significantly greater EAC SPLs ipsilateral to the oscillator at 2000 and 4000 Hz. We conclude that forehead placement of a BC vibrator may help to lessen the (unwanted) contribution of the EAC to measurements of hearing sensitivity by BC.

Audiometry, Pure-Tone↗
PubMed1992

Professional attitudes regarding counseling of hearing-impaired adults.

To determine contemporary thinking regarding initial counseling of hearing-impaired adults 500 questionnaires were mailed to otologists and otolaryngologists and 500 to clinical audiologists. Usable questionnaires total 136 for the former group and 266 for the latter. Some significant differences were found in the ways clinicians saw themselves as counselors and in the needs they perceived their patients as having. Respondents reported experiencing various methods of training and possessing diverse attitudes about the effectiveness of their preparation as counselors during their professional training.

Adult↗
PubMed1991

Characterization of circular mitochondrial plasmids in three Pythium species.

Four circular plasmids, with a monomer size ranging from 3.2 to 4.94 kb, have been identified in isolates of P. aphanidermatum (two different plasmids), P. torulosum, and an unidentified echinulate isolate. The mitochondrial location has been confirmed for three of the plasmids. Each fungal isolate contained a single plasmid, present in both monomeric and oligomeric forms; plasmid monomers were present as open circles and as supercoiled forms. Restriction maps of the plasmids were dissimilar. Hybridization studies using cloned plasmids revealed no DNA sequence similarity among the different plasmids or between the plasmids and the nuclear or mitochondrial genome of the isolates from which they were recovered. Hybridization of labeled plasmid DNA to Northern transfers of mitochondrial RNA for two isolates indicate that what appears to be the predominant RNA transcript is unit length in size. For three isolates, the plasmid was retained following subculturing and was present in all asexual and sexual single-spore progeny evaluated. For one isolate of P. aphanidermatum the plasmid was unstable and was lost during subculturing.

Blotting, Northern↗
PubMed1991

Insert earphones for speech recognition testing.

Performance-intensity functions for PB word lists were run on 19 normal-hearing subjects and 15 subjects with sensorineural hearing losses. Comparisons were made between standard supra-aural earphones (TDH-49P) and insert phones (ER-3A). Results showed that, at least for the higher sensation levels where word recognition tests are usually performed, the phones may be used interchangeably. Using insert earphones for word recognition tests can have several beneficial effects with respect to cross hearing and masking.

Adult↗
PubMed1986

A modified spondee threshold procedure.

Since Martin and Sides (Asha, 1985, 27, 29-36) found that only 6% of audiologists reported actually following current ASHA guidelines for SRT testing (Asha, 1979, 21, 353-356), a comparison was made on 36 normal-hearing adults of spondee thresholds (ST) collected following strictly those guidelines (ST1) and by an experimental procedure based on the ASHA guidelines for pure-tone audiometry (Asha, 1978, 20, 297-301) (ST2). A 3-frequency pure-tone average (PTA) was also collected. Since mean HTLs differed by less than or equal to 5 db among ST1, ST2, and PTA, both ST procedures appear equally valid and interchangeable, but ST2 was considerably more efficient, requiring less time (mean savings of 139 sec/ear) and fewer word presentations (mean savings of 15 words/ear). The ST2 procedure may have clinical use with no significant compromise in validity.

Adult↗
PubMed1985

Speech reception thresholds using conventional vs high-frequency spondees in normals and in subjects with marked high-frequency sensorineural loss.

Spondee threshold (ST) estimates were obtained on 20 normal-hearing adults and 15 adults with high-frequency sensorineural hearing losses sloping off above 500 c/s at about 15-20 db/oct. Stimuli consisted of tapes of a woman's voice speaking permuted lists of 9 conventional (broadband) spondees and of 10 high-frequency-emphasis spondees developed especially for this research using a discrete-frequency analysis. For normals, the correspondence was good between the 3-frequency (.5, 1, 2 kc/s) PTA vs either list. However, for the sensorineural Ss, the mean ST for the conventional spondees was better matched to the 2-frequency PTA (av. of 2 best of .5, 1, 2 kc/s), while the high-frequency-emphasis list STs were better matched to the 3-frequency PTA. It was suggested that high-frequency-emphasis STs be used with such sloping losses and that ST-PTA reliability checks for such Ss be comparisons using a +/- 5-db criterion comparing high-frequency-emphasis STs with 3-frequency PTA. If conventional STs are collected, they should with such Ss be compared to the individual's 2-frequency PTA.

Adult↗
PubMed1983

Syllabic stress (trochaic vs. spondaic) and speech thresholds in normal and hearing-impaired children.

Speech thresholds for 6 common two-syllable words on tape with either trochaic (natural) or spondaic stress were collected from children aged 3.5-6.5 yrs, audiometrically grouped as normal-hearing (N:8), conductive (N:8) or sensorineural (N:6). Ss were further grouped as younger and older. No significant differences in mean threshold, nor in time to reach threshold, were observed for either pattern of stress or age, suggesting that audiologists may interchange spondaic with trochaic stress when measuring speech thresholds in young children, with no effect on the mean value or the efficiency of the threshold (mn of .5, 1, and 2 kc/s) or on its correlation with the pure-tone HTL.

Age Factors↗
PubMed1981

The influence of syllabic stress on children's speech reception thresholds.

One tape exemplar of each words cowboy, baseball, airplane, cupcake, popcorn, and hotdog spoken with natural (trochaic) and again with unnatural (spondaic) stress were selected from a pool to collect monaural SRTs by earphone in children. There were no significant differences due to type of stress, nor between boys and girls. Older children (N: 16, aged 5.0--6.0 yrs; SRT = --0.2 db HL) exhibited lower SRTs than younger (N: 16, aged 3.0--4.0 yrs; SRT = 3.2 db HL). It was informally observed that response, especially in younger Ss, tended (even when correct) to be at a slower rate, a condition to which the clinician should be alert.

Age Factors↗
PubMed1981

On the relationship of stapedial contraction to central masking.

The auditory masked threshold of a 1-kc/s pure tone was determined in quiet and with levels of white noise at 50-80 db SL in the non-test ear. Two groups of normal-hearing adults were tested, one (N:14, mn age = 27.4 yrs) with no history of middle-ear pathology, and another (N:12, mn age = 44.7 yrs) with the stapedial tendon severed. Significant differences in the amount of masked-threshold shift were observed, greater shifts being seen for the normal Ss, additional shifts ranging from 0.8-4.3 db as masking increased from 50-80 db SL. These differences were judged to be at least partly the result of stapedial contraction rather than having their origin entirely in central masking as often assumed.

Adolescent↗
PubMed1979

Comparison of tangibly reinforced speech-reception and pure-tone thresholds of mentally retarded children.

Sixteen mentally retarded children who had normal hearing were examined with two tests of auditory sensitivity. One procedure employed a tangibly reinforced operant-conditioning paradigm for pure tones, and the other test was based on a modification of operant conditioning for obtaining speech-reception thresholds. The speech procedure, utilizing an attractive mechanical device in the form of a clown, proved to be effective and efficient for use with retarded children.

Acoustic Stimulation↗
PubMed1978

Measurement of speech thresholds of Spanish-speaking children by non-Spanish speaking clinicians.

This study investigated the feasibility of a prerecorded speech threshold procedure that was used in a picture-pointing format, and was administered to Spanish-speaking children by non-Spanish-speaking clinicians. The derived Spanish word list was compared for equivalency to English spondees on a group of bilingual adults. The test, administered to 16 children ages three to six years, resulted in good agreement between SRT and pure-tone average. The test was found to be feasible, rapid, and reliable.

Adult↗
PubMed1977

Effects of sophistication on four tests for nonorganic hearing loss.

Three groups of 15 normal-hearing subjects were asked to simulate a hearing loss in one ear. Each subject was then tested on four measurements often used in determining the presence of pseudohypacusis (a comparison of the SRT to the pure-tone average, ascending vs descending pure-tone tests, the Stenger test, and pure-tone delayed auditory feedback). Results showed that as practice and sophistication on each of the procedures increased, there tended to be more improvement in the subjects' ability to "beat" some of the tests than others.

Adult↗