Relation of Pure Tone Thresholds to Background Noise Level in the Atlantic Cod (Gadus morhua)

1968 ◽  
Vol 25 (6) ◽  
pp. 1155-1160 ◽  
Author(s):  
Udo Buerkle
Keyword(s):  
Noise Level ◽  
Background Noise ◽  
Pure Tone ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Noise Levels ◽  
Conditioning Procedure ◽  
Signal To Noise ◽  
Auditory Thresholds ◽  
Four Levels

A conditioning procedure was used to determine auditory thresholds of cod at frequencies 35.3, 70.7, 141, 283, and 400 Hz at four levels of background noise. The noise was produced in octave bands centered at the test frequencies, and ranged in level from −14 db to +4 db (re 1 microbar). Up to 283 Hz thresholds varied directly with background noise, and signal-to-noise levels at thresholds remained approximately the same at all background noise levels for each frequency. Thresholds at 400 Hz were much higher and showed no relationship to noise. Mean signal-to-noise levels are calculated.

An Audiogram of the Atlantic Cod, Gadus morhua L.

1967 ◽  
Vol 24 (11) ◽  
pp. 2309-2319 ◽  
Author(s):  
Udo Buerkle
Keyword(s):  
Electric Shock ◽  
Background Noise ◽  
Cardiac Rhythm ◽  
Conditioned Response ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Absolute Threshold ◽  
High Sensitivity ◽  
Experimental Tank ◽  
Auditory Thresholds

Auditory thresholds were determined by means of a conditioned response to sound stimuli at frequencies 17.6, 35.3, 70.7, 141, 283, and 400 cycles/sec for 10 cod, Gadus morhua. The conditioned response was a change of cardiac rhythm. It was established through an electric shock as unconditioned stimulus, and could be monitored on an oscilloscope.The thresholds indicated cod to have high sensitivity to sounds up to 283 cycles/sec. At 400 cycles/sec they were relatively deaf. Background noise in the experimental tank was high enough to influence thresholds; an absolute threshold could therefore not be determined.

Most Comfortable Listening Levels, Background Noise Levels, and Acceptable Noise Levels for Children and Adults with Normal Hearing

2011 ◽  
Vol 22 (05) ◽  
pp. 286-293 ◽  
Author(s):  
Robert Moore ◽  
Susan Gordon-Hickey ◽  
Alisha Jones
Keyword(s):  
Young Adults ◽  
Noise Level ◽  
Background Noise ◽  
Developmental Change ◽  
Pediatric Population ◽  
Strong Predictor ◽  
Normal Hearing ◽  
Noise Levels ◽  
Cross Sectional ◽  
The Difference

Background: For adults the acceptable noise level (ANL) has been shown to be a strong predictor of hearing aid success. ANL is calculated as the difference between most comfortable listening level (MCL) and background noise level (BNL). No studies have made direct comparisons of these measures between adults and children. Purpose: To evaluate and compare MCLs, BNLs, and ANLs in children and young adults. Research Design: A cross-sectional design was used in this study. Two groups (children and adults) were tested for each dependent variable. MCLs and BNLs were measured for each participant, and ANLs were computed from these two measurements. Study Sample: The participants were 34 children (8–10 yr) and 34 young adults (19–29 yr) with normal hearing. Results: Significant main effects were found for MCLs and BNLs. There was no main effect for ANLs. MCLs and BNLs were significantly lower for the children than for the adults. Conclusions: These results suggest that while ANLs are unchanged from childhood to adulthood, there appears to be a developmental change in MCLs and BNLs. These findings have implications for the use of ANLs in the pediatric population.

Auditory Masking and the Critical Band in Atlantic Cod (Gadus morhua)

1969 ◽  
Vol 26 (5) ◽  
pp. 1113-1119 ◽  
Author(s):  
Udo Buerkle
Keyword(s):  
Noise Level ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Critical Band ◽  
Frequency Separation ◽  
Auditory Masking ◽  
Masking Noise

Auditory masking was determined for cod by using five half-octave bands as masking stimuli and as signals. For each of 15 cod, masking noise was kept constant at 10 db re 1 microbar in one band while thresholds were determined for signals in all five bands. Results indicate masking to be most pronounced when noise and signal coincide in frequency, and to drop off as frequency separation between noise and signal increases. Masking is calculated in terms of threshold in relation to masking noise level, and varies from about 11 db when signal and noise are in the same band to about −19 db when they are in bands furthest removed from each other. Estimates of critical bands are made from the results.

scholarly journals Evaluation of Different Signal Processing Options in Unilateral and Bilateral Cochlear Freedom Implant Recipients Using R-SpaceTM Background Noise

2011 ◽  
Vol 22 (02) ◽  
pp. 065-080 ◽  
Author(s):  
Alison M. Brockmeyer ◽  
Lisa G. Potts
Keyword(s):  
Speech Recognition ◽  
Noise Level ◽  
Repeated Measures ◽  
Background Noise ◽  
Processing Condition ◽  
Test System ◽  
Adaptive Beamforming ◽  
Processing Conditions ◽  
Noise Levels ◽  
Speech Recognition In Noise

Background: Difficulty understanding in background noise is a common complaint of cochlear implant (CI) recipients. Programming options are available to improve speech recognition in noise for CI users including automatic dynamic range optimization (ADRO), autosensitivity control (ASC), and a two-stage adaptive beamforming algorithm (BEAM). However, the processing option that results in the best speech recognition in noise is unknown. In addition, laboratory measures of these processing options often show greater degrees of improvement than reported by participants in everyday listening situations. To address this issue, Compton-Conley and colleagues developed a test system to replicate a restaurant environment. The R-SPACE™ consists of eight loudspeakers positioned in a 360 degree arc and utilizes a recording made at a restaurant of background noise. Purpose: The present study measured speech recognition in the R-SPACE with four processing options: standard dual-port directional (STD), ADRO, ASC, and BEAM. Research Design: A repeated-measures, within-subject design was used to evaluate the four different processing options at two noise levels. Study Sample: Twenty-seven unilateral and three bilateral adult Nucleus Freedom CI recipients. Intervention: The participants’ everyday program (with no additional processing) was used as the STD program. ADRO, ASC, and BEAM were added individually to the STD program to create a total of four programs. Data Collection and Analysis: Participants repeated Hearing in Noise Test sentences presented at 0 degrees azimuth with R-SPACE restaurant noise at two noise levels, 60 and 70 dB SPL. The reception threshold for sentences (RTS) was obtained for each processing condition and noise level. Results: In 60 dB SPL noise, BEAM processing resulted in the best RTS, with a significant improvement over STD and ADRO processing. In 70 dB SPL noise, ASC and BEAM processing had significantly better mean RTSs compared to STD and ADRO processing. Comparison of noise levels showed that STD and BEAM processing resulted in significantly poorer RTSs in 70 dB SPL noise compared to the performance with these processing conditions in 60 dB SPL noise. Bilateral participants demonstrated a bilateral improvement compared to the better monaural condition for both noise levels and all processing conditions, except ASC in 60 dB SPL noise. Conclusions: The results of this study suggest that the use of processing options that utilize noise reduction, like those available in ASC and BEAM, improve a CI recipient's ability to understand speech in noise in listening situations similar to those experienced in the real world. The choice of the best processing option is dependent on the noise level, with BEAM best at moderate noise levels and ASC best at loud noise levels for unilateral CI recipients. Therefore, multiple noise programs or a combination of processing options may be necessary to provide CI users with the best performance in a variety of listening situations.

A Signal-to-Noise Ratio Model for the Speech-Reception Threshold of the Hearing Impaired

1986 ◽  
Vol 29 (2) ◽  
pp. 146-154 ◽  
Author(s):  
Reinier Plomp
Keyword(s):  
Hearing Aids ◽  
Noise Level ◽  
Signal To Noise Ratio ◽  
Hearing Impaired ◽  
Noise Levels ◽  
Threshold Elevation ◽  
Signal To Noise ◽  
Speech Reception ◽  
Noise Ratio ◽  
Two Parameters

This paper reviews the results of a series of investigations inspired by a model of the speech-reception threshold (SRT) of hearing-impaired listeners. The model contains two parameters accounting for the SRT of normal-hearing listeners (SRT in quiet and signal-to-noise ratio corresponding to the threshold at high noise levels), two parameters describing the hearing loss (attenuation and threshold elevation in terms of signal-to-noise ratio), and three parameters describing the hearing aid (acoustic gain, threshold elevation expressed in signal-to-noise ratio, and equivalent internal noise level). Experimental data are reported for three different types of hearing impairment: presbycusis, hearing losses with a pathological origin, and noise-induced losses. The model gives an excellent description of the data. It demonstrates that for many hearing-impaired persons speech intelligibility at noise levels beyond 50 to 60 dB(A) is their main problem, whereas hearing aids are most effective below that noise level.

scholarly journals Synchrony as a measure of conversation difficulty: Movement coherence increases with background noise level and complexity in dyads and triads

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258247
Author(s):  
Lauren V. Hadley ◽  
Jamie A. Ward
Keyword(s):  
Head Movement ◽  
Noise Level ◽  
Background Noise ◽  
Task Difficulty ◽  
Motion Tracking ◽  
Verbal Information ◽  
Noise Levels ◽  
Background Noise Level ◽  
Low Levels ◽  
Movement Synchrony

When people interact, they fall into synchrony. This synchrony has been demonstrated in a range of contexts, from walking or playing music together to holding a conversation, and has been linked to prosocial outcomes such as development of rapport and efficiency of cooperation. While the basis of synchrony remains unclear, several studies have found synchrony to increase when an interaction is made challenging, potentially providing a means of facilitating interaction. Here we focus on head movement during free conversation. As verbal information is obscured when conversing over background noise, we investigate whether synchrony is greater in high vs low levels of noise, as well as addressing the effect of background noise complexity. Participants held a series of conversations with unfamiliar interlocutors while seated in a lab, and the background noise level changed every 15-30s between 54, 60, 66, 72, and 78 dB. We report measures of head movement synchrony recorded via high-resolution motion tracking at the extreme noise levels (i.e., 54 vs 78 dB) in dyads (n = 15) and triads (n = 11). In both the dyads and the triads, we report increased movement coherence in high compared to low level speech-shaped noise. Furthermore, in triads we compare behaviour in speech-shaped noise vs multi-talker babble, and find greater movement coherence in the more complex babble condition. Key synchrony differences fall in the 0.2–0.5 Hz frequency bands, and are discussed in terms of their correspondence to talkers’ average utterance durations. Additional synchrony differences occur at higher frequencies in the triads only (i.e., >5 Hz), which may relate to synchrony of backchannel cues (as multiple individuals were listening and responding to the same talker). Not only do these studies replicate prior work indicating interlocutors’ increased reliance on behavioural synchrony as task difficulty increases, but they demonstrate these effects using multiple difficulty manipulations and across different sized interaction groups.

DE-NOISING AND BASELINE WANDERING REMOVAL OF ELECTROCARDIOGRAM USING DOUBLE DENSITY DISCRETE WAVELET

2007 ◽  
Vol 05 (03) ◽  
pp. 399-415 ◽  
Author(s):  
R. SHANTHA SELVA KUMARI ◽  
V. SADASIVAM
Keyword(s):  
Noise Level ◽  
Signal To Noise Ratio ◽  
Discrete Wavelet ◽  
Signal To Noise ◽  
Wavelet Approximation ◽  
Baseline Wandering ◽  
Noise Ratio ◽  
Four Levels ◽  
Approximation Coefficients ◽  
Different Levels

In this paper, an off-line double density discrete wavelet transform based de-noising and baseline wandering removal methods are proposed. Different levels decomposition is used depending upon the noise level, so as to give a better result. When the noise level is low, three levels decomposition is used. When the noise level is medium, four levels decomposition is used. When the noise level is high, five levels decomposition is used. Soft threshold technique is applied to each set of wavelet detail coefficients with different noise level. Donoho's estimator is used as a threshold for each set of wavelet detail coefficients. The results are compared with other classical filters and improvement of signal to noise ratio is discussed. Using the proposed method the output signal to noise ratio is 19.7628 dB for an input signal to noise ratio of -7.11 dB. This is much higher than other methods available in the literature. Baseline wandering removal is done by using double density discrete wavelet approximation coefficients of the whole signal. This is an unsupervised method allowing the process to be used in off-line automatic analysis of electrocardiogram. The results are more accurate than other methods with less effort.

Natural Speech Intelligibility in Theatres in Relation to Their Acoustics

2011 ◽  
Vol 18 (3-4) ◽  
pp. 293-311
Author(s):  
Maarten P.M. Luykx ◽  
Martijn L.S. Vercammen
Keyword(s):  
Background Noise ◽  
Speech Intelligibility ◽  
Signal To Noise Ratio ◽  
Speech Sound ◽  
Sound Level ◽  
Natural Speech ◽  
Noise Levels ◽  
Signal To Noise ◽  
Background Levels ◽  
Noise Ratio

There is a certain tendency in the design of theatres to make the halls quite large. From a perspective of natural speech intelligibility and strength of speech this is disadvantageous, because an actor's voice has a certain, limited loudness and consequently the signal-to-noise ratio at the listener may become too low. Based on the influence of signal/noise ratio on speech intelligibility, it is deduced that the strength G ≥ 6 dB and room volumes have to be limited to 4000–4500 m3 in order to maintain sufficient loudness for natural speech. Sound level measurements during performances with natural speech in a theatre have been performed, to determine background noise levels in the hall due to the audience and to investigate the signal-to-noise ratio of the actors voice at the audience. The background levels are mainly determined by installation noise and not by the influence of the audience.

scholarly journals Effect of noise in blending and deblending

Geophysics ◽  
2013 ◽  
Vol 78 (5) ◽  
pp. A35-A38 ◽  
Author(s):  
Guus Berkhout ◽  
Gerrit Blacquière
Keyword(s):  
Noise Level ◽  
Background Noise ◽  
Signal To Noise Ratio ◽  
Interesting Consequence ◽  
Signal To Noise ◽  
Background Noise Level ◽  
Noise Ratio ◽  
Incoherent Source ◽  
Large Background

If simultaneous shooting is carried out by incoherent source arrays, being the condition of blended acquisition, the deblending process generates shot records with a very low residual interference (blending noise). We found, theoretically and numerically, that deblended shot records had a better background-related signal-to-noise ratio than shot records in unblended surveys. This improvement increased with increasing blending fold and decreasing survey time. An interesting consequence of this property is that blended surveys can be carried out under more severe noise conditions than unblended surveys. It is advisable to optimize the survey time in areas with a large background noise level or in areas with severe environmental restrictions.

Effects of continuous noise backgrounds on rate response of auditory nerve fibers in cat

1984 ◽  
Vol 51 (6) ◽  
pp. 1326-1344 ◽  
Author(s):  
J. A. Costalupes ◽  
E. D. Young ◽  
D. J. Gibson
Keyword(s):  
Auditory Nerve ◽  
Noise Level ◽  
Background Noise ◽  
Dynamic Range ◽  
Discharge Rate ◽  
Nerve Fibers ◽  
Noise Levels ◽  
High Noise ◽  
Continuous Noise ◽  
Auditory Nerve Fibers

This study describes the effects of broadband background noise on the average discharge rate to best-frequency (BF) tones of auditory nerve fibers in the cat. The effects of exposure to long-term continuous noise are compared to the effects of noise gated on and off simultaneously with test tones. Addition of background noise causes a shift of the dynamic portion of tone-evoked rate versus level functions to higher tone intensities. The shift occurs at a mean rate of 0.61 dB of shift for each 1-dB increment in noise level. The rate of shift is independent of best frequency and spontaneous discharge rate. The noise level at which the shift begins is frequency dependent and is consistent with the frequency-dependent bandwidths of auditory nerve fiber tuning curves. The adjustment of the dynamic range shows many similarities to two-tone suppression. Therefore, it is most likely that it is caused by suppression of the response to the BF test tone by energy present in the noise at surrounding frequencies. At high noise levels, the ability of auditory nerve fibers to respond to test tones is limited by the rate response to the noise. As noise level increases, the discharge rate it evokes approaches a fiber's saturation rate and ultimately eliminates the fiber's ability to respond to test tones. Low spontaneous rate fibers, which have been shown to have higher thresholds and wider dynamic range (17,29), are significantly more resistant to saturation by high noise levels. Exposure to broadband noise prior to onset of test tones produces an overall decrement in response rate. This phenomenon is similar to the effects of short-term adaptation (32) and seems to develop independently of the shift of dynamic range. At high noise levels, previous exposure to the noise produces a small dynamic range shift. This effect is similar to that produced by suppression but is smaller. The effect is occluded in continuous noise backgrounds by the adjustment of sensitivity produced by suppression.

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