Masking of Auditory Responses in the Medulla Oblongata of Goldfish

1973 ◽  
Vol 59 (2) ◽  
pp. 415-424
Author(s):  
PER S. ENGER
Keyword(s):  
White Noise ◽  
Background Noise ◽  
Nervous Activity ◽  
Band Width ◽  
Masking Effect ◽  
Noise Band ◽  
Octave Band ◽  
Tone Frequency ◽  
Centre Frequency ◽  
Pure Tones

1. The nervous activity of single auditory neurones in goldfish brain have been measured. 2. Four types of acoustic stimuli were used, (1) pure tones, (2) noise of one-third octave band width, (3) noise of one-octave band width with centre frequency equal to the pure tone, and (4) white noise. 3. Except for white noise, these stimuli produced the same response to equal sound pressures. The white noise response was less, presumably because the frequency range covered by a single neurone is far narrower than the range of white noise. 4. The conclusion has been reached that for low-frequency acoustic signals, the acoustic power over a frequency band of one to two octaves is integrated by the nervous system. 5. The masking effect of background noise on the acoustic threshold of single units to pure tones is strongest when the noise band has the same centre frequency as the test tone. In this case the tone threshold increases linearly with the background noise level. 6. When the noise band was centred at a different frequency from the tone, the masking effect decreased at a rate of 20-22 dB/octave for the first one-third octave for a tone frequency of 250 Hz. For a tone of 500 Hz the masking effect of lower frequencies was stronger and was reduced by only some 9 dB/octave for the first one-third octave.

Comparative Bekesy Typing with Broad and Modulated Narrow-Band Noise

1969 ◽  
Vol 12 (4) ◽  
pp. 840-846
Author(s):  
Charles T. Grimes ◽  
Alan S. Feldman
Keyword(s):  
White Noise ◽  
Narrow Band ◽  
Band Width ◽  
Masking Effect ◽  
Type Ii ◽  
Noise Masking ◽  
Narrow Band Noise ◽  
Band Noise ◽  
Continuous Tone ◽  
Békésy Audiometry

This study explored the effectiveness of modulated narrow-band noise as a masking source for sweep-frequency Bekesy audiometry. Five sophisticated normal-hearing subjects traced Bekesy audiometry thresholds for pulsed and continuous tone with no masking and under three conditions of contralateral masking: (1) white noise, (2) modulated narrow-band noise with a constant band-width of ±150 Hz, and (3) modulated narrow-band noise with a band-width of ±300 Hz. Results indicated that the continuous tone tracing obtained under the second condition separated from the pulsed tracing supportive of a Type II tracing. With the third condition, pulsed-continuous differences were somewhat smaller. Under the first condition, the difference between pulsed and continuous tracings was not apparent. When two unsophisticated subjects were tested with the modified band-width noise, results indicated extreme variation between pulsed and continuous tracings. We concluded that the masking effect of a constant band-width modulated narrow-band noise is about the same as that of white noise for a pulsed tone tracing. However, the use of a modulated narrow-band noise masking source may cause false Type II Bekesy audiograms due to the greater masking effect on a continuous tone threshold.

scholarly journals Modeling and Mapping of Combined Noise Annoyance for Aircraft and Road Traffic Based on a Partial Loudness Model

2021 ◽  
Vol 18 (16) ◽  
pp. 8724
Author(s):  
Wonhee Lee ◽  
Chanil Chun ◽  
Dongwook Kim ◽  
Soogab Lee
Keyword(s):  
Background Noise ◽  
Road Traffic ◽  
Noise Source ◽  
Transportation Systems ◽  
Masking Effect ◽  
Noise Sources ◽  
Noise Annoyance ◽  
Short And Long Term ◽  
Loudness Model

Complex transportation systems often produce combined exposure to aircraft and road noise. Depending on the noise source, the annoyance response is different, and a masking effect occurs between the noise sources within the combined noise. Considering these characteristics, partial loudness was adopted to evaluate noise annoyance. First, a partial loudness model incorporating binaural inhibition was proposed and validated. Second, short- and long-term annoyance models were developed using partial loudness. Finally, the annoyance of combined noise was visualized as a map. These models can evaluate the annoyance by considering both the intensity and frequency characteristics of the noise. In addition, it is possible to quantify the masking effect that occurs between noise sources. Combined noise annoyance maps depict the degree of annoyance of residents and show the background noise effect, which is not seen on general noise maps.

Repetition enhances hearing detection thresholds in a harbour seal (Phoca vitulina)

1993 ◽  
Vol 71 (5) ◽  
pp. 926-932 ◽  
Author(s):  
S. D. Turnbull ◽  
J. M. Terhune
Keyword(s):  
White Noise ◽  
Background Noise ◽  
Phoca Vitulina ◽  
Harbour Seal ◽  
Detection Thresholds ◽  
Noise Masking ◽  
Phoca Groenlandica ◽  
Hearing Thresholds ◽  
Lower Detection ◽  
Pinniped Species

Pure-tone hearing thresholds of a harbour seal (Phoca vitulina) were measured in air and underwater using behavioural psychophysical techniques. A 50-ms sinusoidal pulse was presented in both white-noise masked and unmasked situations at pulse repetition rates of 1, 2, 4, and 10/s. Test frequencies were 0.5, 1.0, 2.0, 4.0, and 8.0 kHz in air and 2.0, 4.0, 8.0, and 16.0 kHz underwater. Relative to 1 pulse/s, mean threshold shifts were −1, −3, and −5 dB at 2, 4, and 10 pulses/s, respectively. The threshold shifts from 1 to 10 pulses/s were significant (F = 12.457, df = 2,36, p < 0.001) and there was no difference in the threshold shifts between the masked and unmasked situations (F = 2.585; df = 1,50; p > 0.10). Broadband masking caused by meteorological or industrial sources will closely resemble the white-noise situation. At high calling rates, the numerous overlapping calls of some species (e.g., harp seal, Phoca groenlandica) present virtually continous "background noise" which also resembles the broadband white-noise masking situation. An implication of lower detection thresholds is that if a seal regularly repeats short vocalizations, the communication range of that call could be increased significantly (80% at 10 pulses/s). This could have important implications during the breeding season should storms or shipping noises occur or when some pinniped species become increasingly vocal and the background noise of conspecifics increases.

scholarly journals Monolingual and Bilingual Word Recognition and Word Learning in Background Noise

2019 ◽  
Vol 63 (2) ◽  
pp. 381-403 ◽  
Author(s):  
Giovanna Morini ◽  
Rochelle S. Newman
Keyword(s):  
Word Recognition ◽  
White Noise ◽  
Object Relations ◽  
Word Learning ◽  
Background Noise ◽  
Learning Task ◽  
Growing Up ◽  
Linguistic Experience ◽  
Speech In Noise

The question of whether bilingualism leads to advantages or disadvantages in linguistic abilities has been debated for many years. It is unclear whether growing up with one versus two languages is related to variations in the ability to process speech in the presence of background noise. We present findings from a word recognition and a word learning task with monolingual and bilingual adults. Bilinguals appear to be less accurate than monolinguals at identifying familiar words in the presence of white noise. However, the bilingual “disadvantage” identified during word recognition is not present when listeners were asked to acquire novel word-object relations that were trained either in noise or in quiet. This work suggests that linguistic experience and the demands associated with the type of task both play a role in the ability for listeners to process speech in noise.

Comparison of Seven Systems for High-Frequency Air-Conduction Audiometry

1970 ◽  
Vol 13 (2) ◽  
pp. 254-270 ◽  
Author(s):  
Cecil K. Myers ◽  
J. Donald Harris
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Frequency Noise ◽  
Noise Band ◽  
Frequency Range ◽  
Pure Tones ◽  
Auditory Acuity ◽  
Narrow Bands ◽  
Reference Threshold ◽  
Air Conduction

Seven equipment systems were assembled to examine human auditory acuity from 8 to 20 kHz. Two loudspeakers and two earphones were examined, together with two types of stimulus (pure tones and narrow bands of noise) and two psychometric methods (Limits and Adjustments). All systems were capable of providing usably reliable thresholds on 28 ears throughout the whole frequency range. When carefully calibrated, several systems (those involving loudspeakers, as well as those involving earphones) yielded comparable reference threshold sound-pressure levels at the eardrum. A preference was expressed for a system using Bekesy threshold tracking with a changing-frequency noise band of 300 Hz, and for a discrete-tone system using the Method of Constants.

Effect of contralateral pure tone stimulation on distortion emissions suggests a frequency-specific functioning of the efferent cochlear control

2012 ◽  
Vol 107 (7) ◽  
pp. 1962-1969 ◽  
Author(s):  
H. Althen ◽  
A. Wittekindt ◽  
B. Gaese ◽  
M. Kössl ◽  
C. Abel
Keyword(s):  
White Noise ◽  
Otoacoustic Emissions ◽  
Pure Tone ◽  
Specific Effect ◽  
Outer Hair Cells ◽  
Efferent Activity ◽  
Distortion Product ◽  
Frequency Specificity ◽  
Olivocochlear System ◽  
Pure Tones

Contralateral acoustic stimulation (CAS) with white noise and pure tone stimuli was used to assess frequency specificity of efferent olivocochlear control of cochlear mechanics in the gerbil. Changes of the cochlear amplifier can be monitored by distortion product otoacoustic emissions (DPOAEs), which are a byproduct of the nonlinear amplification by the outer hair cells. We used the quadratic DPOAE f2-f1 as ipsilateral probe, as it is known to be sensitive to efferent olivocochlear activity. White noise CAS, used to evoke efferent activity, had maximal effects on the DPOAE level for f2-stimulus frequencies of 5–7 kHz. The dominant effect during CAS was a DPOAE level increase of up to 13.5 dB. The frequency specificity of the olivocochlear system was evaluated by presenting pure tones (0.5–38 kHz) as contralateral stimuli to evoke efferent activity. Maximal DPOAE level changes were triggered by CAS frequencies close to the frequency of the DPOAE elicitor tones (tested f2 range: 2.5–15 kHz). The effective CAS frequency range covered 1.4–2.4 octaves and was centered 0.42 octaves below the DPOAE elicitor tone f2. The frequency-specific effect of CAS with pure tones suggests a dedicated central control of mechanical adjustments for peripheral frequency processing.

scholarly journals Increment and decrement tone frequency effects in English-speaking adults

2019 ◽  
Author(s):  
Alycia Erin Cummings ◽  
Amebu Seddoh
Keyword(s):  
Mismatch Negativity ◽  
Event Related Potential ◽  
Oddball Paradigm ◽  
High Pitch ◽  
Tone Frequency ◽  
Frequency Effects ◽  
Standard Tone ◽  
Stimulus Set ◽  
English Speaking ◽  
Pure Tones

Mismatch negativity (MMN) has been shown to vary in amplitude and latency depending on deviance magnitude. However, how tone deviance direction affects its generation is poorly understood due to paucity of data. The present study sought to determine whether increment and decrement frequencies with deviance magnitudes of 20, 40, and 50 Hz yield differential MMN responses. English-speaking adults were presented two sets of standard and deviant pure tones in a passive event-related potential (ERP) oddball paradigm. Both stimulus sets had the same standard tone of 200 Hz. Each standard tone was accompanied by a set of either increment or decrement deviant tones. The increment tones were 220, 240, and 250 Hz, and the decrement tones were 180, 160, and 150 Hz. Thus, regardless of direction, deviance magnitudes were kept the same at 20 Hz, 40 Hz, and 50 Hz across each stimulus set. Results showed that ERP amplitudes varied according to deviance direction. Decrement stimuli of 160 Hz and 150 Hz elicited larger MMN responses than their corresponding increment stimuli (240 Hz and 150 Hz). These outcomes are consistent with data that indicate that the perception of low and high pitch is mediated by differential discrimination thresholds.

scholarly journals Lizards speed up visual displays in noisy motion habitats

2007 ◽  
Vol 274 (1613) ◽  
pp. 1057-1062 ◽  
Author(s):  
Terry J Ord ◽  
Richard A Peters ◽  
Barbara Clucas ◽  
Judy A Stamps
Keyword(s):  
Puerto Rican ◽  
Background Noise ◽  
Visual Signals ◽  
Acoustic Properties ◽  
Masking Effect ◽  
Environmental Constraints ◽  
Visual Displays ◽  
Noisy Environments ◽  
Communication Signals ◽  
Speed Up

Extensive research over the last few decades has revealed that many acoustically communicating animals compensate for the masking effect of background noise by changing the structure of their signals. Familiar examples include birds using acoustic properties that enhance the transmission of vocalizations in noisy habitats. Here, we show that the effects of background noise on communication signals are not limited to the acoustic modality, and that visual noise from windblown vegetation has an equally important influence on the production of dynamic visual displays. We found that two species of Puerto Rican lizard, Anolis cristatellus and A. gundlachi , increase the speed of body movements used in territorial signalling to apparently improve communication in visually ‘noisy’ environments of rapidly moving vegetation. This is the first evidence that animals change how they produce dynamic visual signals when communicating in noisy motion habitats. Taken together with previous work on acoustic communication, our results show that animals with very different sensory ecologies can face similar environmental constraints and adopt remarkably similar strategies to overcome these constraints.

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