Changes In Loudness Research Articles

Acoustic and aerodynamic characteristics of Country‐Western, Operatic and Broadway singing styles compared to speech

Acoustic and aerodynamic measures were used to objectively describe characteristics of Country‐Western (C‐W) singing in a group of six premier performers in a series of studies and of operatic and Broadway singing in a female subject with professional experience in both styles of singing. For comparison purposes the same measures also were applied to individuals while speaking the same material as sung. Changes in pitch and vocal loudness were investigated for various dependent variables, including subglottal pressure, closed quotient, glottal leakage, H1–H2 difference [the level difference between the two lowest partials of the source spectrum and glottal compliance (the ratio between the air volume displaced in a glottal pulse and the subglottal pressure)], formant frequencies, long‐term‐average spectrum and vibrato characteristics (in operatic versus Broadway singing). Data from C‐W singers suggest they use higher sub‐glottal pressures in singing than in speaking. Changes in vocal intensity for doublin...

Hemispheric asymmetries in the perception of rapid (timbral) and slow (nontimbral) amplitude fluctuations of complex tones.

Hemispheric asymmetries for processing rapid (timbral) and slow (nontimbral) amplitude fluctuations of complex tones were investigated in 32 right-handed nonmusicians. Two monaural matching-to-sample tests with contralateral white noise and attention directed to 1 ear were used, 1 with tones presenting slow fluctuations of amplitude and 1 with tones presenting rapid fluctuations of amplitude perceived as different timbres. Stimuli were generated by altering the amplitude envelope of a steady state complex tone. Dependent variables were reaction time and accuracy. The results suggest an important role for the right hemisphere in the perception of temporal variations of intensity of sounds both when these variations are rapid and perceived as timbral qualities and when they are slow and perceived as changes of loudness.

The influence of pitch and loudness changes on the acoustics of vocal tremor.

The effect of tremor on phonation is to modulate an otherwise steady sound source in its amplitude, fundamental frequency, or both. The severity of untreated vocal tremor has been reported to change under certain conditions that may be related to muscle tension. In order to better understand the phenomenon of vocal tremor, its acoustic properties were examined as individuals volitionally altered their pitch and loudness. These voice conditions were anticipated to alter the tension of the intrinsic laryngeal muscles. The voices of 10 individuals with a diagnosis of vocal tremor were recorded before participating in a longitudinal treatment study. They produced vowels at low and high pitch and loudness levels as well as in a comfortable voice condition. Acoustic analyses quantified the amplitude and frequency modulations of the speakers' voices across the various conditions. Individual speakers varied in the way the pitch and loudness changes affected their tremor, but the following statistically significant effects for the speakers as a group were observed: Higher pitch phonation was associated with a more rapid rate for both amplitude and frequency modulations. Amplitude modulation become faster for louder phonation. Low-pitched phonotion led to decreases in the extent of amplitude tremor. Varying pitch led to dramatic changes in the phase relationship between amplitude and frequency modulation in some of the speakers, whereas this effect was not apparent in other speakers.

Interaction of speech coders and atypical speech II: effects on speech quality.

We investigated how standard speech coders, currently used in modern communication systems, affect the quality of the speech of persons who have common speech and voice disorders. Three standardized speech coders (GSM 6.10 RPE-LTP, FS1016 CELP, and FS1015 LPC) and two speech coders based on subband processing were evaluated for their performance. Coder effects were assessed by measuring the quality of speech samples both before and after processing by the speech coders. Speech quality was rated by 10 listeners with normal hearing on 28 different scales representing pitch and loudness changes, speech rate, laryngeal and resonatory dysfunction, and coder-induced distortions. Results showed that (a) nine scale items were consistently and reliably rated by the listeners; (b) all coders degraded speech quality on these nine scales, with the GSM and CELP coders providing the better quality speech; and (c) interactions between coders and individual voices did occur on several voice quality scales.

An Investigation into Music Found to Trigger Peak Emotional Experiences during Controlled Listening Experiments

Peak emotional experiences can be triggered inter alia by music (Maslow 1962). 74 college staff members, from a population previously surveyed for incidences of such experiences, listened to music selections under controlled conditions and recorded the timings of any peak events that might have occurred. An attempt was then made to identify and analyse points in the music that had triggered high incidences of peaks, such as changes in harmony, key or loudness. Although there were individual differences, at the macro level the recorded peaks during 25 to 30 minutes of gentle music revealed an alternating high-low response pattern between different pieces, but such a trend was less obvious with upbeat items. Some reasons for these findings are suggested. The results may have value for those who use music for healing purposes, especially music therapists, and for composers or compilers of music programmes who need to anticipate listener reaction.

The Doppler effect is not what you think it is: dramatic pitch change due to dynamic intensity change.

Historically, auditory pitch has been considered to be a function of acoustic frequency, with only a small effect being due to absolute intensity. Yet we found that when tones are Doppler shifted so that frequency drops, the pitch dramatically rises and falls, closely following the pattern of dynamic intensity change. We show that continuous intensity change can produce pitch variation comparable to a frequency change approaching an octave. This effect opposes and is an order of magnitude larger than the well-known effect of discrete intensity change in the frequency range employed. We propose that the perceptual interaction of continuous changes in pitch and loudness reflects a natural correlation between changes in frequency and intensity that is neurally encoded to facilitate the parsing and processing of meaningful acoustic patterns.

Brain imaging of the effects of lidocaine on tinnitus

Using a single-blind placebo-controlled design, we mapped lidocaine related changes in neural activity, measured by regional cerebral blood flow (rCBF) with 15O-H 2O positron emission tomography. Intravenous lidocaine produced both increases and decreases in the loudness of tinnitus. The change in tinnitus loudness was associated with a statistically significant change in neural activity in the right temporal lobe in auditory association cortex. Decreases in tinnitus loudness resulted in larger changes in rCBF than increases. The unilateral activation pattern associated with tinnitus, in contrast with the bilateral activation produced by a real sound, suggests that tinnitus originates in the central auditory system rather than the cochlea. In addition, generalized lidocaine effects were found in the basal ganglia, thalamus, and a region spanning the Rolandic fissure.

Evoking terror in film scores

Evoking terror in film scores

Pitch and loudness interact in auditory displays: can the data get lost in the map?

Many auditory displays use acoustic attributes such as frequency, intensity, and spectral content to represent different characteristics of multidimensional data. This study demonstrated a perceptual interaction between dynamic changes in pitch and loudness, as well as perceived asymmetries in directional acoustic change, that distorted the data relations represented in an auditory display. Three experiments showed that changes in loudness can influence pitch change, that changes in pitch can influence loudness change, and that increases in acoustic intensity are judged to change more than equivalent decreases. Within a sonification of stock market data, these characteristics created perceptual distortions in the data set. The results suggest that great care should be exercised when using lower level acoustic dimensions to represent multidimensional data.

The non-classical auditory pathways are involved in hearing in children but not in adults

Auditory information ascends through the brainstem to the cerebral cortices in two parallel pathways, known as the classical and the non-classical ascending auditory pathways. The importance of the non-classical auditory pathway for hearing in humans is unknown but its subcortical connection to limbic structures may be important in tinnitus. In this study we show evidence that non-classical pathways are involved in loudness perception in young individuals but not in adults. We used the fact that some neurons in the non-classical auditory pathways receive somatosensory input and we determined the effect on loudness perception of monaural sounds from electrical stimulation of the median nerve at the wrist. Stimulation of the somatosensory system had the greatest effect on loudness perception in the youngest children that we studied (7–8 years) and the effect was minimal for individuals above 20 years of age. The effect was an increase in loudness in 20 of the 40 individuals we studied and a decrease in 4 individuals; 16 experienced no noticeable change in loudness during somatosensory stimulation.

Comb filters for binaural dichotic presentation to improve speech perception by persons with bilateral sensorineural hearing impairment

Intelligibility of speech for persons with sensorineural hearing impairment gets reduced due to increased spectral masking. For persons with bilateral loss, improved speech perception has been reported with binaural dichotic presentation using comb filters having complementary magnitude responses, based on auditory critical bands. In this scheme, spectral components in adjacent critical bands do not mask each other as they get presented to different ears. The objective here was to design a set of comb filters with transition crossovers adjusted for a low perceived spectral distortion. For this, a slowly swept tone presented through the two comb filters should not have a change in its perceived loudness at crossover frequencies. Experiments showed that the change in loudness was negligible with crossover response lying between −4 dB and −6 dB with respect to passband response. With this constraint for response at the crossover frequencies, comb filters with responses corresponding to 18 critical bands were designed as 256-coefficient linear phase FIR filters, using frequency sampling technique. The filters have pass band ripple of 1 dB and stop band attenuation of 30 dB. These filters have resulted in improvement in speech quality and speech perception.

An Adaptive Bias in the Perception of Looming Auditory Motion

Rising acoustic intensity can indicate movement of a sound source toward a listener. Perceptual overestimation of intensity change could provide a selective advantage by indicating that the source is closer than it actually is, providing a better opportunity for the listener to prepare for the source's arrival. In Experiment 1, listeners heard equivalent rising and falling level sounds and indicated whether one demonstrated a greater change in loudness than the other. In 2 subsequent experiments listeners heard equivalent approaching and receding sounds and indicated perceived starting and stopping points of the auditory motion. Results indicate that rising intensity changed in loudness more than equivalent falling intensity, and approaching sounds were perceived as starting and stopping closer than equidistant receding sounds. Both effects were greater for tones than for noise. Evidence is presented that suggests that an asymmetry in the neural coding of egocentric auditory motion is an adaptation that provides advanced warning of looming acoustic sources.

Effectiveness of Ginkgo biloba in treating tinnitus: double blind, placebo controlled trial

Objective: To determine whether Ginkgo biloba is effective in treating tinnitus.Design: Double blind, placebo controlled trial using postal questionnaires.Participants: 1121 healthy people aged between 18 and 70 years with tinnitus...

The control of carrier frequency in cricket calls: a refutation of the subalar-tegminal resonance/auditory feedback model.

The subalar-tegminal resonance/auditory feedback hypothesis attempts to explain how crickets control the carrier frequency (f(C)), the loudness and the spectral purity of their calls. This model contrasts with the 'clockwork cricket' or escapement model by proposing that f(C) is not controlled by the resonance of the cricket's radiators (the harps) but is instead controlled neurally. It suggests that crickets are capable of driving their harps to vibrate at any frequency and that they use a tunable Helmholtz-like resonator consisting of the tegmina and the air within the subalar space to amplify and filter the f(C). This model predicts that f(C) is variable, that call loudness is related to tegminal position (and subalar volume) and that low-density gases should cause f(C) to increase. In Anurogryllus arboreus, f(C) is not constant and varied by as much as 0.8 % between pulses. Within each sound pulse, the average f(C) typically decreased from the first to the last third of a sound pulse by 9 %. When crickets called in a mixture of heliox and air, f(C) increased 1.07- to 1.14-fold above the value in air. However, if the subalar space were part of a Helmholtz-like resonator, then its resonant frequency should have increased by 40-50 %. Moreover, similar increases occurred in species that lack a subalar space (oecanthines). Experimental reduction of the subalar volume of singing crickets resulted neither in a change in f(C) nor in a change in loudness. Nor did crickets attempt to restore the subalar volume to its original value. These results disprove the presence of a subalar-tegminal resonator. The free resonance of freshly excised Gryllus rubens tegmina shifted by 1.09-fold when moved between air and a mixture of helium and air. Auditory feedback cannot be the cause of this shift, which is similar to the f(C) shifts in intact individuals of other species. Calculations show that the harp is 3.9-1.8 times more massive than the air that moves en masse with the vibrating harps. Replacing air with heliox-air lowers the mass of the vibrating system sufficiently to account for the f(C) shifts. These results re-affirm the 'clockwork cricket' (escapement) hypothesis. However, as realized by others, the harps should be viewed as narrow-band variable-frequency oscillators whose tuning may be controlled by factors that vary the effective mass.

Perception of changes in loudness

Neuhoff replies — Canevet and his colleagues suggest that their findings address dynamic loudness change and are inconsistent with my recent discovery of a bias for rising intensity tones1. However, the two sets of experiments address fundamentally different questions. Canevet et al. 's listeners were asked to make judgements about loudness, whereas my listeners were asked to make judgements about the amount of dynamic change. Essentially, their listeners answered the question “How loud is it now?” by assigning a number to the loudness of a changing intensity sound at various times throughout the stimulus duration. This provided a discrete measure of loudness at various snapshots in time. Listeners in my experiments were specifically asked to ignore the overall loudness of the sounds and to make summary judgements about the amount of loudness change, essentially answering the question “How much did it change in loudness?”.

A privileged perceptual status for rising intensity tones

Recent cross-modal matching experiments have shown that listeners reliably overestimate the change of rising level tones relative to equivalent falling level tones [J. G. Neuhoff, Nature 395 (6698), 123–124 (1998)]. In a natural listening environment this overestimation could provide a selective advantage, because rising intensity can signal source movement toward an organism. In the present work, listeners heard equivalent rising and falling level tones, and in a three-alternative forced-choice task, indicated which sound demonstrated the greatest change in loudness, or whether the amount of loudness change was the same. If one sound was judged to change more than the other, listeners indicated the magnitude of disparity in loudness change between the two sounds. Results indicate a privileged perceptual status for rising intensity tones, and a greater perceptual disparity between rising and falling intensity tones as overall level increases. These results suggest an asymmetry in the neural coding of tonal rising and falling intensity sweeps, and may be indicative of localization priorities in a natural listening environment.

Evaluation of a physiological ear model for the simulation of nonlinear masking effects

A physiological model of the human auditory system with the aim at generating masked thresholds for arbitrary sound signals was presented at the previous DEGA meeting. The main parts of the ear model are an active nonlinear cochlear model and a threshold detector which evaluates changes in specific loudness. It was shown that the ear model is able to rebuild the level dependency of spectral and temporal masking patterns, the asymmetry of masking between noise and tone, and the different detection thresholds for amplitude and frequency modulation. This study presents new simulation results for nonlinear masking effects. These results indicate that the nonlinear ear model allows demonstration of other nonlinear psychoacoustical effects such as the additivity of masking, suppression, and distortion product detection. Since the physiological ear model represents a unified approach covering the most important masking effects of arbitrary sounds, it is suitable for applications such as perceptual audio coding. An improved coding efficiency is expected due to the more accurate masked thresholds generated by the ear model in comparison to results from psychoacoustical models commonly used in audio coding which neglect many of the nonlinear effects of auditory perception. [Work supported by DFG.]

Space-induced distortion of starting transient of musical sound

Musical sound can be defined as complex sound that begins with a starting transient followed by a (more or less) steady sound and ends with a decaying sound. After that, continuous movement from one frequency to the another follows. The rate of change of loudness for partial tones that are greater than a certain threshold and their relative starting times are different for miscellaneous musical instruments. Recognition of a particular musical instrument depends upon short starting and ending transients. Relative starting time of the starting transient’s partial is limited by the rate of change of loudness that is greater than 600 dB/s. The envelope of all rates of change defines the maximum rate of change for loudness levels and partials that dominates in a certain time interval. The beginning transient is the complex phenomena, assessed with early sound and rate and synchronized with the rise of loudness and dominant partial tone in the observed time interval. The just-noticeable threshold of rates of loudness change for partial tones for various musical instruments in different acoustically treated spaces was measured and described in this paper.

Parameterization of the voice source by combining spectral decay and amplitude features of the glottal flow.

A new method is presented for the parameterization of glottal volume velocity waveforms that have been estimated by inverse filtering acoustic speech pressure signals. The new technique, Parameter for Spectral and Amplitude Features of the Glottal Flow (PSA), combines two features of voice production, the AC value and the spectral decay of the glottal flow, both of which contribute to changes in vocal loudness. PSA yields a single parameter that characterizes the glottal flow in different loudness conditions. By analyzing voices of 8 speakers it was shown that the new parameter correlates strongly with the sound pressure level of speech.

Intensity discrimination for precedence effect stimuli.

When two identical stimuli are presented from two loudspeakers with a brief delay between them, a single image is heard near the source of the leading sound. The delayed sound or echo appears to be suppressed whereas the preceding sound determines perceived location, hence the name, the precedence effect. This study investigated normal-hearing listeners' sensitivity to changes in the intensity of the lagging sound. Pairs of 2-ms white noise bursts, with a 2-ms delay between the onsets of lead and lag, were presented from two loudspeakers 45 degrees left and right of midline in an anechoic chamber. A 2AFC procedure was used to test discrimination of intensity changes in the lead, lag, and both sounds together. The untreated results showed discrimination to be poorest for changes in the lag stimulus. However, when the intensity differences were transformed into predictions of equivalent monaural level based on KEMAR measurements and binaural loudness summation, discrimination for the lag was equal to the other two conditions. A follow-up experiment found that listeners were highly sensitive to the presence of the lag, more sensitive than would be predicted from loudness changes. It is concluded that the precedence effect does not consist of a general suppression or attenuation of the lagging sound, but rather that suppression may be limited to directionality cues.