Andrzej Wicher

Adam Mickiewicz University | UAM · Institute of Acoustics

Binaural beats brain stimulation is a popular strategy for supporting home-use cognitive tasks. However, such home-use brain stimulation may be neutral to cognitive processes, and any intellectual improvement may be only a placebo effect. Thus, without belief in it, it may bring no benefits. Here we test 1000 individuals at their homes as they perf...

Background: Hearing loss caused by excessive exposure to noise is one of the most common health risks for employees. One solution for noise reduction is the use of hearing protectors, which is a very effective method for protecting hearing from the workplace noise. In order to obtain better attenuation efficiency, custom moulded earplugs can be equ...

Objectives Many tinnitus subjects report problems with communication, in particular, difficulties with the intelligibility of speech when it is presented in the background of noise. The type of tinnitus (tone-like, noise, etc.), its location and range in the frequency domain, and the type and degree of accompanying hearing loss can affect speech in...

Background: Hearing loss caused by excessive noise levels is one of the most common health risks for employees. One solution for noise reduction is the use of hearing protectors, which is one of the most effective methods for protecting hearing from noise at the workplace. In order to obtain different attenuation efficiency, individual hearing prot...

The efferent system may control the gain of the cochlea and thereby influence frequency selectivity. This effect can be assessed using contralateral stimulation (CS) applied to the ear opposite to that used to assess frequency selectivity. The effect of CS may be stronger for musicians than for nonmusicians. To assess whether this was the case, psy...

The impulse noise produced by personal weapons (guns, rifles, shotguns) during military activity, and while people engage in sport, training and hunting, is a threat to the auditory systems of soldiers, civilians, policemen, hunters, forest officers, sportspeople and bystanders not actively engaged in professional or recreational firing. An overvie...

Musicians are better than non-musicians at discriminating changes in the fundamental frequency (F0) of harmonic complex tones. Such discrimination may be based on place cues derived from low resolved harmonics, envelope cues derived from high harmonics, and temporal fine structure (TFS) cues derived from both low and high harmonics. The present stu...

The main purpose of this research was to determine the influence of a therapeutic dose of an opioid drug (methadone) on selected auditory functions in patients addicted to opioids (recognition ICD-10; F11) and undergoing substitution therapy. Various hearing tests were used in this research – pure tone audiometry, impedance audiometry, otoacoustic...

To determine speech intelligibility using the test suggested by Ozimek et al. (2009), the subject composed sentences with the words presented on a computer screen. However, the number and the type of these words were chosen arbitrarily. The subject was always presented with 18, similarly sounding words. Therefore, the aim of this study was to deter...

The main aim of this study was to determine the influence of different type of contralateral signals on the level of distortion product otoacoustic emissions (DPOAEs). Four types of contralateral signals (CS) were used in the study: broadband noise, pink noise, the babble noise and speech presented against a babble masking noise. DPOAEs were measur...

The relative effectiveness of narrowband and broadband noises in activating the efferent system was assessed by comparing the effect of contralateral stimulation (CS) with such sounds on psychophysical tuning curves (PTCs) determined in simultaneous masking, using signal frequencies of 1000 or 2000 Hz. To check that the CS stimuli used did activate...

The main purpose of this investigation was to measure the effect of contralateral acoustic stimulation (CAS) on distortion product otoacoustic emission (DPOAE) in twenty human ears, for a ratio of primary tones f(2)/f(1) = 1.22 and a wide frequency range of f(2) (1.4-9 kHz), for two intensity levels of primary tones (L-1 = 60 dB SPL; L-2 = 50 dB SP...

Objectives: The aim of this study is to assess the relationship between the use of opioid drugs and speech intelligibility and discrimination of sound frequencies. Methods: 44 opioid addicts (10 women and 34 men) during methadone maintenance treatment were examined. The mean age of participants 33±9 years; the average duration of addiction: 12 year...

Objectives: The aim of research is to assess a speech perception in alcohol addicts and healthy ones. Methods: 65 alcohol addicts (mean age 38 years, min. 22, max. 66 years) were examined. Patients admitted hearing impaired were excluded. The average duration of addiction: 8.8 years. The measure of speech understanding is the ratio of correctly rec...

The speech intelligibility for different configurations of a target signal (speech) and masker (babble noise) in a horizontal and a median plane was investigated. The sources were placed at the front, in the back or in the right hand side (at different angular configurations) of a dummy head. The speech signals were presented to listeners via headp...

The main aim of this work was to determine the influence of contralateral stimulation (CS) on the psychophysical tuning curves (PTCs) and distortion product otoacoustic emissions (DPOAEs). PTCs and DPOAEs were measured in two modes: in the presence or absence of CS. The contralateral signal was a wideband noise (bandwidth 0.2-10 kHz) at a level of...

The main purpose of this work was to describe an influence of contralateral stimulation (CS) on distortion products otoacoustic emissions (DPOAEs) and psychophysical tuning curves (PTCs). The fast method for determining PTCs was used in the study. DPOAEs and PTCs were measured in two modes: in the presence or absence of CS. The CS was a broadband n...

The LED light therapy and magnetostimulation is an innovative method of treatment used in Viofor JPS System. Simultaneous application of both types of electromagnetic radiation increases the therapy effectiveness by the Synergy effect. It is recommended in analgesic, anti-inflammatory treatment, and to Support immune System of the organism. The mec...

Contralateral Stimulation of the auditory System causes changes in levels of otoacoustic emissions. The main objective of this study was to determine the changes in the level of distortion product otoacoustic emissions for contralaterally presented unmodulated broad-band noise, or amplitude modulated broad-band noise. Two types of modulating signal...

One of the methods for objective evaluation of the hearing system is based on acoustic otoemissions. Particularly promising is the method based on measurement of the distortion product of otoacoustic emission as it is connected to the problem of tinnitus. Slow-varying magnetic field of low induction has been used in therapy of many diseases and ail...

The aim of the study was to determine the effect of hearing loss on speech intelligibility in tinnitus patients. Two new Polish tests for speech intelligibility measurements (the Polish Sentence Test-PST and the Polish Digit Triplet Test-PDTT) were used in the investigation. Tinnitus patients (56 persons) with bilateral sensorineural hearing loss a...

Psychophysical tuning curves (PTCs) can be used to assess the frequency selectivity of the auditory system and to detect and delimit “dead regions” in the cochlea. However, the traditional method for determining PTCs takes too long for use in clinical practice. We evaluated a fast method for determining PTCs, using a band of noise that sweeps in ce...

The aim of this study was to develop Polish sentence tests for accurate measuring of speech intelligibility in masking interfering noise. Two sets of sentence lists have been developed. The first set was composed of 25 lists and was used for sentence intelligibility scoring. The second set was composed of 22 lists and was used for word intelligibil...

The objective of this study was to develop and evaluate the Polish digit triplet test for speech intelligibility screening. The first part of the paper deals with the preparation of the speech material, the recording procedure and a listening experiment. In this part, triplet-specific intelligibility functions for 160 different digit complexes were...

The objective of this study was to develop and evaluate the Polish digit triplet test for speech intelligibility screening. The first stage of the work deals with the preparation of the test and the recording procedure. The second part presents results of the digit triplets intelligibility measurement and retest data. The test consists of 4 statist...

Psychophysical tuning curves (PTCs) are usually measured by determining the level of a narrowband noise required just to mask a fixed,' low-level tone, for several masker centre frequencies. PTCs are often used to assess the frequency selectivity of the auditory system and they have also been used to detect "dead regions" in the cochlea, especially...

The aim of this study was to determine the effect of tinnitus (experiment I) and the combined effect of tinnitus and sensorineural hearing loss (experiment II) on the distortion product otoacoustic emission (DPOAE) for two age groups of tinnitus patients. Tinnitus patients with normal earing, along with normal-hearing control subjects, participated...

The main purpose of this study was to prepare Polish sentence tests for measuring speech intelligibility against an interfering noise. The tests were developed from meaningful sentences taken from everyday utterances, TV, literature etc. Two sets of sentence lists were created. The first set was optimized for the so-called binary scoring and was co...

Psychophysical tuning curves (PTCs) can be used to assess the frequency selectivity of the auditory system and to detect and delimit "dead regions" in the cochlea. However, the traditional method for determining PTCs takes too long for use in clinical practice. We evaluated a fast method for determining PTCs, using a band of noise that sweeps in ce...

The purpose of the study was to determine the effect of tinnitus and total effect of tinnitus and the hearing loss function on the distortion product otoacoustic emission. Tinnitus patients were selected to exhibit normal hearing and such tinnitus patients who exhibited the increasing or notch-like sensorineural hearing loss. It was found that the...

Abnormalities in the cochlear function usually cause broadening of the auditory filters which reduces the speech intelligibility. An attempt to apply a spectral enhancement algorithm has been undertaken to improve the identification of Polish vowels by subjects with cochlear-based hearing-impairment. The identification scores of natural (unprocesse...

The study reported was undertaken as an attempt to improve the intelligibility of selected speech signals (numerical test) masked by a speech-shaped noise, by a proposed algorithm of the speech signal processing based on the spectral contrast enhancement and binaural procedure. The spectral contrast enhancement involved the transformation of the sp...

The study deals with the binaurally perceived modulation depth (m p ) of amplitude‐modulated signals (Exp. I) and binaurally perceived frequency deviation (Δf p ) of frequency‐modulated signals (Exp. II), for their diotic and dichotic perception. Various combinations of modulation depth (m) and frequency deviation (Δf) at the left and right ear wer...

Subjects estimated pitches of signals which were similar to sounds that appear as a result of a room response to a sinusoidal impulse with a rectangular envelope. A shift of pitch of the investigated sounds was observed, as well as its relation to calculated values of the magnitude of complex instantaneous sound frequency. Therefore it can be assum...

The article reports on development of a Polish Sentence Test for accurate and reliable speech intelligibility measurements against noise. The Polish material is composed of 481 different sentences divided into 37 lists of 13 sentences each. All the lists are phonemically and statistically balanced, i.e. the respective lists reveal comparable phonem...