1,721,008 research outputs found
The detection of ‘virtual’ objects using echoes by humans: spectral cues
No full textThese data comprise of binaural impulse responses as reported in the paper: "The detection of ‘virtual’ objects using echoes by humans: spectral cues" by Rowan et al in Hearing Research 2017.
Each file is a .wav file containing the binaural impulse responses (IRs) – see our Hearing Research paper for details. IRs are available for four rooms (LAC = large anechoic chamber; RevCh = reverberation chamber). The filename for each wav file is constructed with the following components:
Room label (r1, r2, r3 or r4)
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Object distance (0 = no object; otherwise distance in meters from 0,5 to 5).
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Version of recording (a, b or c are simple repeats of same conditions; ‘without_board’ indicates that the pole on which the board was mounted was present but the board itself was removed)
.wav
Note that a small set of distances was used for Room 3.
For more information, please contact Daniel Rowan [email protected]
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Learning to discriminate interaural time differences
No full textEThOS - Electronic Theses Online ServiceGBUnited Kingdo
Lateralization of high frequency pure tones with interaural phase difference and bone conduction
No full textThis study tested the prediction that interaural phase differences (IPDs) are converted to interaural level differences (ILDs) with bilateral bone-conduction stimulation due to the effects of acoustic interference arising from transcranial transmission. Seven normal-hearing listeners judged the lateral position of 3000-6000-Hz pure tones, presented via bone vibrators on the mastoids, as a function of IPD. Evidence for lateralization was obtained in five listeners despite humans being insensitive to IPD in pure tones at these frequencies. The direction of lateralization depended on frequency, as well as IPD, for three listeners. It is argued that these findings are consistent with the conversion of external IPD to internal ILD during transcranial transmission. Inter-individual variation in lateralization was apparent and no evidence of lateralization was found in two listeners at the frequency tested, which may reflect, at least in part, inter-individual variation in transcranial transmission properties. The notion that external IPD within the waveform fine-structure at high-frequencies does not influence localization with air conduction may not apply to bone conduction due to the acoustic interference effects
Learning to discriminate interaural time differences at low and high frequencies
No full textThis study investigated learning, in normal-hearing
adults, associated with training (i.e. repeated practice)
on the discrimination of ongoing interaural time difference
(ITD). Specifically, the study addressed an apparent
disparity in the conclusions of previous studies, which
reported training-induced learning at high frequencies
but not at low frequencies. Twenty normal-hearing adults
were trained with either low- or high-frequency stimuli,
associated with comparable asymptotic thresholds, or
served as untrained controls. Overall, trained listeners
learnt more than controls and over multiple sessions. The
magnitudes and time-courses of learning with the lowand
high-frequency stimuli were similar. While this is
inconsistent with the conclusion of a previous study with
low-frequency ITD, this previous conclusion may not be
justified by the results reported. Generalization of learning
across frequency was found, although more detailed
investigations of stimulus-specific learning are warranted.
Overall, the results are consistent with the notion that
ongoing ITD processing is functionally uniform across
frequency. These results may have implications for clinical
populations, such as users of bilateral cochlear implants
Generalisation of learning with ITD discrimination across frequency and type of cue
No full textA previous study¹ compared the ability of normal–hearing ‘naïve’ listeners to learn to discriminate low–frequency ongoing interaural time difference (ITD) or high–frequency interaural level difference (ILD), two important cues to localisation. The authors concluded that learning for ILDhad a longer time course and only partially transferred across frequency (~0.6 octaves), interpreted in the context of known differences in the processing of the two cues. Are differences in learning apparent with the discrimination of low–frequency ITD and high–frequency envelope–based ITD cues? We have addressed this using a 128–Hz tone and a 128–Hz tone ‘transposed’ to 4000 Hz; ITD sensitivity with these stimuli is comparable in highly trained listeners², thereby minimising a confounding effect of differential overall sensitivity when interpreting learning.Twenty naïve listeners were trained over 2160 trials with one or other stimulus or served as untrained controls. Performance was measured with both stimuli and sinusoidally amplitude modulated (SAM) tones during pre–and post–training sessions. ITD discrimination was measured using a 1–cue, 3–alternative forced–choice task and listeners were trained using a modified Levitt 2–down, 1–up adaptive procedure³. Overall, performance on pre–training was comparable for unmodulated and transposed stimuli but better than with SAM, although inter–individual variation was apparent. This reinforces the notion that ongoing ITD processing is functionally uniform across frequency. Both training groups learned more than untrained controls but the learning with either trained stimulus transferred entirely to the untrained stimuli. That is, learning generalised across both frequency (~5 octaves) and type of ITD cue. This generalisation may reflect commonality in the necessary listening strategies for optimal performance (e.g. detection of decorrelation) or the pooling across frequency in the underlying processing for ITD discrimination. This research was support by a grant from the Royal National Institute for Deaf People (RNID)1 Wright BA, Fitzgerald MB. Proc Natl Acad Sci USA2001;98:12307–122 Bernstein LR, Trahiotis C. J Acoust Soc Am2002;112:1026–363 Trahiotis C, Bernstein LR, Buell TN, Spektor Z. J AcoustSoc Am 1990;87:1359-6
Learning to discriminate interaural time differences: an exploratory study with amplitude-modulated stimuli. Aprendiendo a discriminar diferencias inter-auriculares de tiempo: un estudio exploratorio con estímulos de amplitud modulada
No full textThe advent of bilateral cochlear implants (CIs) has increased interest in learning on binaural tasks, and studies in normal-hearing listeners provide important background information. However, few studies have considered learning with discrimination of interaural time difference (ITD). Here, learning with ITD was explored using stimuli that are more relevant to bilateral CIs than used previously. Inexperienced listeners were trained with envelope-based ITD using high-frequency amplitude-modulated tones with or without an interaural carrier frequency difference (IFD), the former to simulate asymmetrical bilateral CI insertions. All were tested with and without IFD before and after training. In most listeners, ITD thresholds improved substantially with training, not necessarily reaching asymptote after 3000 trials. In these, the magnitude and time-course of learning was larger than anticipated from a previous study with low-frequency ITD. Learning generalized across IFD and the effect of IFD on ITD thresholds at post-test was smaller than reported previously. These results have implications for studies of bilateral CIs, such as the need to provide extensive training to avoid over-estimating any apparent ‘impairment’.
El advenimiento de los implantes cocleares bilaterales (CI) ha aumentado el interés en aprender sobre tareas binauriculares, y los estudios en sujetos oyentes normales han aportado importante información pertinente. Sin embargo, pocos estudios han considerado el estudio del aprendizaje con base en la discriminación de diferencias interauriculares de tiempo (ITD). Aquí, el aprendizaje con ITD fue explorado utilizando estímulos más relevantes para los CI bilaterales que los usados previamente. Se entrenó a oyentes sin experiencia con una ITD con base en envolventes que comprendían tonos de alta frecuencia de amplitud modulada, con o sin diferencia interauricular de la frecuencia portadora (IFD), esta última para simular inserciones bilaterales asimétricas de CI. Todos fueron evaluados con y sin IFD antes y después del entrenamiento, sin alcanzar necesariamente la asíntota después de 3000 intentos. En ellos, la magnitud y el tiempo del aprendizaje fue mayor de lo anticipado en un estudio con una ITD de baja frecuencia. El aprendizaje en general en todas las IFD y el efecto de la IFD sobre los umbrales de ITD después de la prueba fue similar a los reportes previos. Estos resultados tienen implicaciones en los estudios de CI bilaterales, tales como la necesidad de proveer amplio entrenamiento para evitar la sobre-estimación de cualquier ‘impedimento’ aparente
Use of binaural and monaural cues to identify the lateral position of a virtual object using echoes
No full textUnder certain conditions, sighted and blind humans can use echoes to discern characteristics of otherwise silent objects. Previous research concluded that robust horizontal-plane object localisation ability, without using head movement, depends on information above 2 kHz. While a strong interaural level difference (ILD) cue is available, it was not clear if listeners were using that or the monaural level cue that necessarily accompanies ILD. In this experiment, 13 sighted and normal-hearing listeners were asked to identify the right-vs.-left position of an object in virtual auditory space. Sounds were manipulated to remove binaural cues (binaural vs. diotic presentation) and prevent the use of monaural level cues (using level roving). With low- (<2 kHz) and high- (>2 kHz) frequency bands of noise, performance with binaural presentation and level rove exceeded that expected from use of monaural level cues and that with diotic presentation. It is argued that a high-frequency binaural cue (most likely ILD), and not a monaural level cue, is crucial for robust object localisation without head movement
Development of the Arabic Commands in Noise Test for studying auditory fitness for duty
No full textMilitary employees often work in challenging auditory environments and are required to have appropriate auditory fitness for duty (AFFD). In this project we present the newly developed ‘Arabic Commands in Noise Test’ (ACINT) to study AFFD. Many factors affect auditory performance, including the personality trait conscientiousness, which has not yet been investigated in the context of hearing task performance.The aim of our study is to assess the ability of the ACINT to discriminate between normal-hearing and hearing-impaired individuals. A secondary aim is to explore differences in performance under different listening conditions and performer characteristics, including conscientiousness. The objectives are 1. To assess the test’s ability to distinguish between normal-hearing and hearing-impaired individuals by assessing the sensitivity and specificity of the SIN test to detect mild sensorineural hearing loss (SNHL) and 2. To explore differences in performance under standard and challenging listening conditions between individuals with high and low conscientiousness. Study sample: 54 normal-hearing individuals (low C=17 ,High C=37) and 19 (data collection ongoing) hearing impaired individuals. Results: pending detailed analysis and will be available for discussion in the conference Conclusion: Preliminary data analysis shows that ACINT appears to discriminate between normal hearing individuals and those with mild sensorineural hearing loss documented by audiogram with high specificity
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