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Biomedical subjects

T Frank

Publications and source records attributed to T Frank.

At least 55 records · Page 3Linked to original sources
PubMed1995

Simultaneous comparison between transtympanic and extratympanic electrocochleography.

Electrocochleography (ECoG) has become a mainstay in the diagnostic armamentarium used by otolaryngologists and audiologists in the evaluation of patients suffering auditory and vestibular symptoms. Controversy exists, however, regarding the relative accuracy of ECoG when recorded with a non-invasive external auditory canal (EAC) electrode as compared to that recorded using a transtympanic electrode. In an effort to resolve this controversy, 19 healthy volunteers (37 ears) with no history of otologic disease or symptoms and a normal screening pure-tone audiogram were studied. For each volunteer, a transtympanic electrode was placed on the cochlear promontory bilaterally under iontophoretic anesthesia followed by the immediate placement of an EAC TIPtrode (Etymotic Research Laboratory, Elk Grove Village, Illinois). Signals from both the transtympanic electrode and the TIPtrode were recorded simultaneously following click stimulus using the Nicolet CA 1,000. Preliminary analysis of these recordings identify no significant difference in summating potential/action potential ratios between EAC and transtympanic electrodes in this normal subject population.

Adult↗
PubMed1994

Slicer and tissue retrieval system for excisional endoscopic surgery.

Extraction of large specimens risks detachment of malignant cells within the peritoneal cavity and contamination of the parieties with resultant seedling implantation at the access wounds. Therefore, extraction is best conducted through a rip-proof sleeve-retrieval system which creates a "third space" in which the specimen can be sliced under visual control. Slicing of tissue is preferable to morcellation or disintegration since it preserves the structural integrity of the tissue and thereby does not jeopardize histopathological examination and staging of excised tumors. Of the two types of tissue-slicing mechanisms investigated, the compression-moving blade system (CMB) was found to be superior to wire-cutting devices. A prototype CMB slicer has been developed which has been tested experimentally and is currently undergoing clinical evaluation.

Animals↗
PubMed1994

Ambient noise levels in industrial audiometric test rooms.

In 1983 the Occupational Safety and Health Administration (OSHA) specified maximum permissible ambient noise levels (MPANLs) that would allow valid hearing threshold measurements in an audiometric test room. However, ambient noise sound pressure levels (SPLs) in rooms used for industrial hearing tests are unknown. The present study reports octave band (125 to 8000 Hz) ambient noise SPLs measured in 490 single-walled prefabricated audiometric test rooms located in industrial settings that were obtained from eight sources. The ambient noise SPLs were highest in the lower frequencies and decreased as frequency increased. All 490 rooms met the OSHA MPANLs. Fortunately, the ambient noise SPLs were considerably lower than the OSHA MPANLs, since previous research has demonstrated that hearing thresholds cannot be obtained down to 0-dB HL in a test room having ambient noise levels equal to the OSHA MPANLs. In fact, 33%, or 162 of the 490 test rooms, met the more stringent MPANLs recently specified by the American National Standards Institute (ANSI) for industrial hearing testing. Given that the OSHA MPANLs are too high and that the test room ambient noise SPLs were considerably less than the OSHA MPANLs, that authors recommend that the OSHA MPANLs be revised to the more stringent ANSI 1991 MPANLs so that hearing thresholds for baseline and annual audiograms can be measured down to 0-dB HL.

Audiometry↗
PubMed1993

Acoustical properties of speech produced in noise presented through supra-aural earphones.

This study determined the acoustical properties of speech known as Lombard Speech produced in background noise. Tape recordings were made for ten normally hearing adults (5 women, 5 men) reading connected speech (131 word passage "My Grandfather") at their most comfortable level in quiet and in wideband, traffic, and multitalker noise delivered through earphones at 70 and 90 dB SPL. Spectral analysis of the recordings revealed that, compared with speech in quiet, Lombard speech was characterized by: (1) an increase in overall SPL; (2) smaller vocal pitch shifts for female than male subjects; (3) shifts in spectral distributions of speech energy; and (4) the same spectral slope above 630 Hz regardless of subject gender, noise level, or noise type. Overall, the results of this study do not provide support for the theory that acoustical properties of Lombard speech are identical with loud speech produced in quiet.

Acoustic Stimulation↗
PubMed1993

Ambient noise levels in audiometric test rooms used for clinical audiometry.

Recently, the American National Standards Institute (ANSI) has specified (ANSI S3.1-1991) maximum permissible ambient noise levels (MPANLs) allowed in an audiometric test room that would produce negligible masking of pure tones presented down to O-dB HL for two test conditions (ears covered, ears not covered) and three test frequency ranges (125-8000 Hz, 250-8000 Hz, 500-8000 Hz). In the present study, octave band ambient noise sound pressure levels were measured in 136 audiometric test rooms used for clinical audiometry and compared with the ANSI octave band MPANLs for each test condition and frequency range. For the ears covered condition, about 50% of the rooms were in compliance (passed) with the MPANLs for the 125-8000 Hz and 250-8000 Hz range and 82% for the 500-8000 Hz range. For the ears not covered condition, only about 14% of the rooms passed for the 125-8000 Hz and 250-8000 Hz range and 37% passed for the 500-8000 Hz range. The primary cause of the low pass rate for each test condition and frequency range was attributed to low frequency (125-500 Hz) ambient noise presumably from the ventilation system.

Audiometry↗
PubMed1993

Effects of background noise on earphone thresholds.

Real-ear attenuation at threshold (REAT) and monaural pure-tone thresholds were determined for normally hearing adults using a supra-aural, Audiocup, and insert earphone. The thresholds were obtained in quiet and in background noises approximating the maximum permissible ambient noise levels (MPANLs) allowed in an audiometric test room specified by ANSI S3.1-1991 and OSHA (1983). The supra-aural REAT was less than the Audiocup, which was less than the insert earphone. The mean threshold shifts were negligible regardless of earphone type in the ANSI noise and for the insert earphone in the OSHA noise. Thresholds can be obtained down to 0 dB HL in ANSI 1991 MPANLs using a supra-aural, Audiocup, or insert earphone and in OSHA MPANLs using an insert earphone. However, the OSHA MPANLs are too high and the REAT is too low for a supra-aural earphone and Audiocup for testing down to 0 dB HL.

Adolescent↗
PubMed1992

Attenuation values for a supra-aural earphone for children and insert earphone for children and adults.

Earphone attenuation values were determined for 17 children (6-14 years old) using supra-aural (TDH-49P/Model 51 cushion) and insert earphones (E-A-Rtone 3A) terminated by an E-A-Rlink 3A (for normal size ear canals) or E-A-Rlink 3B (for small size ear canals) foam eartips, and for 10 adults having small ear canals using insert earphones and E-A-Rlink 3B foam eartips. The test signals were 1/3-octave bands of noise presented in a diffuse sound field (re: ANSI S12.6-1984). The supra-aural earphone attenuation values for the children were slightly higher (more attenuation) or similar to reported adult values, and always lower (less attenuation) compared with insert earphone/E-A-Rlink 3A (IE/3A) or 3B (IE/3B) values for both children and adults. The IE/3B attenuation values were similar between the children and adults and provided slightly more attenuation than the IE/3A. Overall, the results indicated that the ANSI S3.1-1991 maximum permissible ambient noise levels allowed in a test room for ears covered testing with a supra-aural earphone, which were determined using adult values, are appropriate for testing children. Future revisions of ANSI S3.1-1991 may include maximum permissible ambient noise levels for testing with insert earphones. The IE/3A and IE/3B attenuation values could be used for that purpose. In the meantime, because more attenuation was provided by the IE/3A and IE/3B, they can be used for testing both children and adults in higher ambient noise levels than specified in ANSI S3.1-1991.

Acoustic Stimulation↗
PubMed1992

Reference threshold levels for an ER-3A insert earphone.

The purpose of this study was to obtain normal hearing thresholds for an ER-3A insert earphone as a contribution for future standardization and for comparison with previous studies and interim ANSI and ISO insert earphone reference equivalent threshold sound pressure levels (RETSPLs). Hearing thresholds were obtained on each ear of 48 normal-hearing subjects from 125 to 8000 Hz using ER-3A and TDH-49P earphones referenced to a Bruel and Kjaer DB-0138 HA-2 and NBS-9A acoustic coupler, respectively. The mean unadjusted and adjusted ER-3A thresholds were in very good agreement with the mean thresholds averaged over eight other studies. Further, the mean adjusted ER-3A thresholds were in very good agreement with the interim ANSI RETSPLs while the mean unadjusted ER-3A thresholds were slightly higher than the ISO RETSPLs. Also, mean ER-3A thresholds averaged over a nine study data base were in closer agreement with the interim ANSI than the ISO RETSPLS. Overall, the interim ANSI insert earphone RETSPLs were recommended for clinical use.

Adolescent↗
PubMed1991

Hearing aid coupler output level variability and coupler correction levels for insert earphones.

HA coupler type SPLs were independently determined by two experimenters for five repeated measurements with and without replacement of two ER-3A and two EARTONE 3A insert earphones. Measurements were made using a B&K DB-0138 coupler configured as an HA-1, HA-2 earphone coupler and HA-2 earphone coupler with entrance through a rigid tube referred to as the DB-0138 coupler. The HA-1, HA-2, and DB-0138 SPLs were found to be very stable (+/- 0.2 dB) for all intra- and interexperimenter measurements for each insert earphone and coupler type from 125 to 8000 Hz. Averaged across both experimenters and all repeated measurements, the mean HA-1 and HA-2 coupler SPLs were similar for each insert earphone from 125 to 8000 Hz. The mean HA-1, HA-2, and DB-0138 coupler SPLs were similar for each insert earphone from 125 to 2000 Hz; however, from 3000 to 8000 Hz the DB-0138 coupler SPLs were higher than the HA-1 and HA-2 coupler SPLs for each insert earphone. This occurred because of the geometrical differences between the insert earphone to coupler connections and coupler types. The HA-1 minus DB-0138 and HA-2 minus DB-0138 coupler SPL differences, or coupler correction levels, could be explained by quarter-wave resonances and stepped-diameter tubing systems creating acoustic horn effects.

Auditory Threshold↗
PubMed1991

Repeatability of high-frequency thresholds.

High-frequency (10, 12, 14, 16, and 18 kHz) thresholds were obtained for each ear of 50 young adults having normal low-frequency hearing across four test sessions separated by at least 1, but no more than 2, weeks using a Beltone 2000 audiometer. The threshold differences between each possible test session comparison (N = 6) were not significantly (p greater than 0.05) different for ear, test session comparison, or frequency. Overall, intrasubject high-frequency thresholds were found to be repeatable and within a clinically acceptable range of +/- 10 dB for at least 94% of the ears, regardless of test session comparison and frequency.

Adult↗
PubMed1990

Attenuation provided by four different audiometric earphone systems.

The attenuation provided by TDH earphones in MX-41/AR and P/N 51 cushions, Audiocup earphone enclosures and ER-3A insert earphones with ER3-14 foam earplugs was determined for 30 normally hearing subjects using a real-ear attenuation at threshold paradigm. The MX-41/AR and P/N 51 cushions provided about the same amount of attenuation which was less than the attenuation provided by the Audiocup enclosures. The ER-3A/ER3-14 provided the highest amount of attenuation. The MX-41/AR and ER-3A/ER3-14 attenuation values were in agreement with other studies using similar methodology. However, the attenuation provided by the Audiocup enclosures was considerably less, in the lower frequencies, than reported in two other studies. ANSI S3.1-1977 supra-aural earphone cushion attenuation values, which were determined using pure-tones presented in a free-field, should be replaced by earphone cushion attenuation values determined with 1/3 octave bands of noise presented in a diffuse sound field.

Adult↗
PubMed1990

High-frequency hearing thresholds in young adults using a commercially available audiometer.

Test and re-test high-frequency (10-20 kHz) thresholds were obtained for 200 ears of 100 normally hearing (0.25-8 kHz) young adults (18-28 years old) using a Beltone 2000 audiometer and Sennheiser HD 250 earphones referenced to sound pressure levels developed in a Bruel and Kjaer flat-plate coupler. Normative high-frequency thresholds could not be recommended for clinical use due to the very large intersubject threshold variability. This occurred even though test versus re-test thresholds were not significantly different (p greater than 0.05) at any frequency. However, comparisons of the test minus re-test threshold for individual ears were within a clinically acceptable range of +/- 10 dB for at least 95% of the ears at each frequency. Future research should concern intrasubject threshold reliability and variability rather than specifying intersubject normative thresholds.

Adolescent↗
PubMed1989

[Antiphlogistic effect of bromelaine following third molar removal].

A placebo-controlled double-blind study of 100 patients with impacted and/or dislocated lower wisdom teeth was conducted to examine the tolerance and antiphlogistic efficacy of bromelaine--a mixture of proteolytic enzymes from ananas comosus. Treatment was started 1 day prior to third molar surgery with a daily dose of 3 x 80 mg and was continued for a total of 6 days. On the 1st day following surgery, linear measurement (distance: tragus-pogonion) showed swelling to be 7.5% lower under drug treatment than in the placebo group. Two-dimensional image evaluation increased this difference to 15.9%, which however still failed to attain the significance level of 20%. Between the 3rd and the 7th postoperative day no differences were found between the two groups regarding the extent of soft tissue swelling or the speed of edema resolution.

Adolescent↗
PubMed1988

Bone conduction threshold levels for different bone vibrator types.

This study determined if bone conduction (BC) thresholds were influenced by vibrator type. BC thresholds were obtained for 100 subjects using mastoid placement of Radioear B-71 and B-72 and Pracitronic KH 70 bone vibrators. The nontest ear was masked (30 dB EL) and the ear ipsilateral to the vibrator was open except when testing at 3000 and 4000 Hz when the ear canal was occluded with an earplug to guard against acoustic radiation. BC thresholds at 250 Hz obtained with the B-72 and KH 70 were significantly (p less than .05) higher by 10.5 dB and at 500 Hz were significantly (p less than .05) lower by 5.5 dB than for the B-71. BC thresholds at other frequencies (1000, 2000, 3000, and 4000 Hz) were not significantly different among vibrator types. The findings indicated that reference equivalent threshold force levels (RETFLs) for BC audiometry should be specified by bone vibrator type.

Adult↗