Search PubMed⌕ Search

Biomedical subjects

P M Haughton

Publications and source records attributed to P M Haughton.

At least 19 recordsLinked to original sources
PubMed1998

Random noise in the spectra of evoked otoacoustic emissions.

Noise from the measuring equipment and from environmental and physiological sources is inevitably present in records of evoked otoacoustic emissions. This paper considers the influence of noise on the power spectra of otoacoustic emissions as recorded with the Otodynamics ILO88 system. It is shown that if the noise has a normal distribution, the ratio of the power in the response spectrum to the power in the noise has an approximately log-normal distribution. It is also shown that the change in the level of the response spectrum that is observed when measurements are repeated is related through a t-distribution to the estimate of the noise-to-signal ratio that these measurements provide. The statistical analysis leads to simple significance tests that may be helpful in detecting the presence of an emission and that allow small changes in the spectrum to be identified.

Acoustic Stimulation↗
PubMed1989

Speech audiometry using an adaptive method.

A curve-fitting method is described whereby the results of an adaptive speech test can be used to obtain an accurate value for the speech reception threshold and an estimate of the slope of the psychometric function in the neighbourhood of this threshold.

Audiometry, Speech↗
PubMed1985

A method for checking the calibration of the Brüel & Kjaer type 8000 mechanical impedance head.

A simple method for calibrating the acceleration and force transducers of the type 8000 mechanical impedance head is described. The accelerometer calibration is referred to the gravitational acceleration, g. The method is limited to frequencies below 500 Hz. The force gauge is calibrated in terms of the force which is registered when a known mass is accelerated sinusoidally at an acceleration which is known from the calibration of the accelerometer.

Acceleration↗
PubMed1982

A system for generating a variable mechanical impedance and its use in an investigation of the electromechanical properties of the B71 audiometric bone vibrator.

A method of presenting a bone vibrator with a variable mechanical load is described. Reciprocal relationships between electrical and mechanical properties of the B71 vibrator have been investigated and it is concluded that the vibrator behaves as a linear, reversible electrodynamic system. The mechanical impedance of the vibrator has been measured in the frequency range 250-4000 Hz. The relevance of these measurements to audiometer calibration and to sound radiation from the vibrator is discussed.

Acoustic Impedance Tests↗
PubMed1981

Normal pure tone thresholds for hearing by bone conduction.

Reference equivalent thresholds on a Brüel and Kjaer artificial mastoid have been obtained from bone conduction measurements made on a group of otologically normal listeners. The results are compared with other recent work. Various methods of presenting reference thresholds are discussed. A new method for masking the non-test ear is described.

Audiometry, Pure-Tone↗
PubMed1979

A forced-choice procedure to detect feigned or exaggerated hearing loss.

A forced-choice technique which may be used to confirm the existence of a non-organic hearing loss is described. Evidence is presented which shows that although this technique is not infallible it can in many cases unmask attempts to simulate or exaggerate a hearing loss. Supplementary tests using conventional audiometry demonstrated that persons with normal hearing can consistently feign a bilateral hearing loss.

Hearing Loss↗
PubMed1977

Validity of tympanometry for middle ear effusions.

The findings on paracentesis and aspiration of the middle ear were compared with preoperative tympanometry. From the results obtained, it was found that if tympanometry alone is used to determine the presence or absence of fluid the best discriminant is a compliance of 0.21 or a gradient of 0.04 equivalent volume units. The average failure rate with either or these criteria is 20%. A numerical estimate of the validity of tympanometry may be made for individual cases.

Audiometry↗