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Biomedical subjects

R R Coles

Publications and source records attributed to R R Coles.

At least 37 records · Page 2Linked to original sources
PubMed1984

The results of cortical electric response audiometry in medico-legal investigations.

Cortical ERA was conducted in a consecutive series of 118 medicolegal cases (467 threshold determination in 209 ears). In organic cases, the distribution of subjective (manual pure tone audiometry)/objective (CERA) discrepancies was normal and centred on 0 dB, with only 3.2% of the discrepancies exceeding + 15 dB. Averaged over 3 or more test frequencies in one ear, only 4.4% of the discrepancies exceeded + 7.5 dB, as compared to 95.1% exceeding + 7.5 dB in those suspected of having a non-organic overlay. The pattern of non-organic overlay superimposed on noise-induced hearing loss is expected and demonstrated to produce a flattening of the dip in the audiogram. It is argued that such flattening is very rarely the end product of noise exposure.

Audiometry↗
PubMed1981

Critical masking bands for sensorineural tinnitus.

The level of noise required to mask tinnitus was measured in 12 subjects with sensorineural tinnitus; the noise was centred on the estimated pitch of the tinnitus, and the overall level required to just mask the tinnitus was measured for masker bandwidths of 2.5, 10, 20, 30 and 50% of the noise centre-frequency. For four of the tinnitus subjects, masking functions were similar to those observed in normal-hearing subjects with a "simulated" tinnitus (15-dB Sensation Level, 4-kHz pure tone). The other eight tinnitus subjects, however, required masking levels that were either independent of masker bandwidth or showed anomalous changes in masker level as bandwidth was increased. These results suggest that certain masker bandwidths can be more efficient than others for the masking of tinnitus, and that masker characteristics deserve close attention in the design and fitting of tinnitus-masker instruments.

Acoustics↗
PubMed1975

Masking of the non-test ear in speech audiometry.

Masking of the non-test ear is often needed in speech audiometry but the methods for such masking have not been well defined. 'White' or 'speech' noise is commonly provided by audiometers for this purpose, and the many problems and uncertainties in their calibration and effectiveness are discussed; data on these aspects are presented with respect to some current audiometers and Fry's and AB(S) PB-word lists. Formulae are given for estimating the possible need for masking, calculating the required dial level of masking noise for a given dial level of speech signal, and assessing the extent to which cross-masking may be affecting the results. The formulae presented are applicable for earphone listening only.

Acoustics↗
PubMed1975

Masking of the non-test ear in tone decay, Békésy audiometry, and SISI tests.

Masking of the non-test ear is frequently required in tone decay, Békésy audiometry and SISI tests; without it, serious misdiagnoses can result. Methods are given for calculating the dial levels of masking noises to be delivered and the extent of possible cross-masking. The methods are subdivided according to whether the tests to be employed are fixed-frequency or sweep-frequency, and to whether masking function data are available from previous use of shadow masking. In difficult cases, careful preliminary shadow-masking procedures and subsequent use of fixed-frequency tests is recommended.

Acoustic Stimulation↗