Reference Sounds Research Articles

Sound properties affect measurement of vocal consistency in birdsong: Validation of the spectrogram cross correlation method (SPCC).

In songbirds, singing with precision (vocal consistency) has been proposed to reflect whole-organism performance. Vocal consistency is measured using spectrogram cross correlation (SPCC) to assess the acoustic similarity between subsequent renditions of the same note. To quantify how SPCC is sensitive to the acoustic discrepancies found in birdsong, we created a set of 40 000 synthetic sounds that were designed based on the songs of 345 species. This set included 10 000 reference sounds and 30 000 inexact variants with quantified differences in frequency, bandwidth, or duration with respect to the reference sounds. We found that SPCC is sensitive to acoustic discrepancies within the natural range of vocal consistency, supporting the use of this method as a tool to assess vocal consistency in songbirds. Importantly, the sensitivity of SPCC was significantly affected by the bandwidth of sounds. The predictions derived from the analysis of synthetic sounds were then validated using 954 song recordings from 345 species (20 families). Based on psychoacoustic studies from birds and humans, we propose that the sensitivity of SPCC to acoustic discrepancies mirrors a perceptual bias in sound discrimination. Nevertheless, we suggest the tool be used with care, since sound bandwidth varies considerably between singing styles and therefore, SPCC scores may not be comparable.

Neural representations of imagined speech revealed by frequency-tagged magnetoencephalography responses

Speech mental imagery is a quasi-perceptual experience that occurs in the absence of real speech stimulation. How imagined speech with higher-order structures such as words, phrases and sentences is rapidly organized and internally constructed remains elusive. To address this issue, subjects were tasked with imagining and perceiving poems along with a sequence of reference sounds with a presentation rate of 4 Hz while magnetoencephalography (MEG) recording was conducted. Giving that a sentence in a traditional Chinese poem is five syllables, a sentential rhythm was generated at a distinctive frequency of 0.8 Hz. Using the frequency tagging we concurrently tracked the neural processing timescale to the top-down generation of rhythmic constructs embedded in speech mental imagery and the bottom-up sensory-driven activity that were precisely tagged at the sentence-level rate of 0.8 Hz and a stimulus-level rate of 4 Hz, respectively. We found similar neural responses induced by the internal construction of sentences from syllables with both imagined and perceived poems and further revealed shared and distinct cohorts of cortical areas corresponding to the sentence-level rhythm in imagery and perception. This study supports the view of a common mechanism between imagery and perception by illustrating the neural representations of higher-order rhythmic structures embedded in imagined and perceived speech.

Walking With Ears: Altered Auditory Feedback Impacts Gait Step Length in Older Adults.

Auditory feedback may provide the nervous system with valuable temporal (e. g., footstep sounds) and spatial (e.g., external reference sounds) information that can assist in the control of upright walking. As such, hearing loss may directly contribute to declines in mobility among older adults. Our purpose was to examine the impact of auditory feedback on the control of walking in older adults. Twenty older adults (65–86 years) with no diagnosed hearing loss walked on a treadmill for three sound conditions: Baseline, Ear Plugs, and White Noise. We hypothesized that in response to reduced temporal auditory feedback during the Ear Plugs and White Noise conditions, participants would adapt shorter and faster steps that are traditionally believed to increase mechanical stability. This hypothesis was not supported. Interestingly, we observed increases in step length (p = 0.047) and step time (p = 0.026) during the Ear Plugs condition vs. Baseline. Taking longer steps during the Ear Plugs condition may have increased ground reaction forces, thus allowing participants to sense footsteps via an occlusion effect. As a follow-up, we performed a Pearson's correlation relating the step length increase during the Ear Plugs condition to participants' scores on a clinical walking balance test, the Functional Gait Assessment. We found a moderate negative relationship (rho = −0.44, p = 0.055), indicating that participants with worse balance made the greatest increases in step length during the Ear Plugs condition. This trend suggests that participants may have actively sought auditory feedback with longer steps, sacrificing a more mechanically stable stepping pattern. We also hypothesized that reduced spatial localization feedback during the Ear Plugs and White Noise conditions would decrease control of center of mass (COM) dynamics, resulting in an increase in lateral COM excursion, lateral margin of stability, and maximum Lyapunov exponent. However, we found no main effects of auditory feedback on these metrics (p = 0.580, p = 0.896, and p = 0.056, respectively). Overall, these results suggest that during a steady-state walking task, healthy older adults can maintain walking control without auditory feedback. However, increases in step length observed during the Ear Plugs condition suggest that temporal auditory cues provide locomotor feedback that becomes increasingly valuable as balance deteriorates with age.

Annoyance penalty of periodically amplitude-modulated wide-band sound.

Amplitude modulation exists in many environmental noise types. A penalty has been suggested for legal noise assessment to such sounds, but the scientific evidence is limited. The purpose of this research was to determine the annoyance penalty of amplitude modulated (AM) sound as a function of the modulation frequency fm and depth Dm. A psychoacoustic laboratory experiment was conducted with 40 participants to explore how subjective loudness and annoyance of AM sound depends on fm (from 0.25 to 16 Hz), Dm (from 1 to 14 dB), and overall spectrum (two alternatives). The sounds consisted of both AM sounds and reference sounds without amplitude modulation. The AM sounds were played at 35 dB LAeq, which is typical for environmental noise both indoors and in residential yards. The annoyance penalty increased with increasing fm and Dm. The penalties varied from 4 to 12 dB, when Dm ranged from 4 to 14 dB and fm ranged from 1 to 16 Hz. For the lowest fm= 0.25 Hz, and Dm = 1 dB, no penalty could be suggested. The results suggest a potential need for a penalty for low-level AM sounds for certain ranges of fm and Dm, applied for the periods with AM sound.

Etnomusiqişünaslıq tehlil üsullarının bestekar yaradıcılığına tetbiqine dair

Avanqard musiqi klassik kanonlari dagitdigina gore tehlil usullarinda bir bosluq yaradaraq musiqisunasliqda da ferqli yanasma terzi teleb etmeye basladi. Harmoniya, forma, orkestrlesdirme usullarinda inqilabi deyisiklikler, minimalistik ifade vasiteleri muvafiq tehlil usullari ve metodologiya yaratmaga vadar etdi. Bu zaman iller uzunu minimalistik tehlil vasitelerini formalasdirmis etnomusiqisunasliq tecrubesi cox yararli gorunmeye basladi. Bestekar musiqisinin intonasiya, tembr, yukseklik, meqam xususiyyetlerine nezeren tehlili ve terminologiyadan istifade musiqinin esil mahiyyetini acmaqda effektiv komekci vasiteye cevrile biler. Arasdirmada esasen E.Alekseyevin erken intonasiya edilme uzre metodologiyasindan istifade edilib. Istifade edilen usul ve metodologiya yekunda dovrun simasini aca bilecek felsefi neticelere gelib cixmaga imkan verir.

Leveraging diversity in computer-aided musical orchestration with an artificial immune system for multi-modal optimization

The aim of computer-aided musical orchestration (CAMO) is to find a combination of musical instrument sounds that perceptually approximates a reference sound when played together. The complexity of timbre perception and the combinatorial explosion of all possible musical instrument sound combinations make it very challenging to find even one orchestration for a reference sound. However, finding only one orchestration is seldom enough given the creative nature of the compositional process. Compositional applications of computer-aided musical orchestration can greatly benefit from multiple orchestrations with diversity. In this work, we use an artificial immune system (AIS) called opt-aiNet to search for combinations of musical instrument sounds that minimize the distance to a reference sound encoded in a fitness function. Opt-aiNet was developed to maximize diversity in the solution set of multi-modal optimization problems, which results in multiple alternative orchestrations for the same reference sound that are different among themselves. We compared the diversity and the similarity of the orchestrations proposed by opt-aiNet (CAMO-AIS) against a standard genetic algorithm (CAMO-GA) and Orchids, which is considered the state of the art for CAMO, for 13 reference sounds. In general, CAMO-AIS outperformed CAMO-GA and Orchids for several measures of objective diversity. We performed a listening test to evaluate and compare the perceptual similarity of the orchestrations by CAMO-AIS and Orchids. CAMO-AIS generated orchestrations that were perceived to be as similar to the reference sounds as those returned by Orchids. Therefore, CAMO-AIS has higher diversity of orchestrations than Orchids without loss of perceptual similarity.

Rising tones and rustling noises: Metaphors in gestural depictions of sounds.

Communicating an auditory experience with words is a difficult task and, in consequence, people often rely on imitative non-verbal vocalizations and gestures. This work explored the combination of such vocalizations and gestures to communicate auditory sensations and representations elicited by non-vocal everyday sounds. Whereas our previous studies have analyzed vocal imitations, the present research focused on gestural depictions of sounds. To this end, two studies investigated the combination of gestures and non-verbal vocalizations. A first, observational study examined a set of vocal and gestural imitations of recordings of sounds representative of a typical everyday environment (ecological sounds) with manual annotations. A second, experimental study used non-ecological sounds whose parameters had been specifically designed to elicit the behaviors highlighted in the observational study, and used quantitative measures and inferential statistics. The results showed that these depicting gestures are based on systematic analogies between a referent sound, as interpreted by a receiver, and the visual aspects of the gestures: auditory-visual metaphors. The results also suggested a different role for vocalizations and gestures. Whereas the vocalizations reproduce all features of the referent sounds as faithfully as vocally possible, the gestures focus on one salient feature with metaphors based on auditory-visual correspondences. Both studies highlighted two metaphors consistently shared across participants: the spatial metaphor of pitch (mapping different pitches to different positions on the vertical dimension), and the rustling metaphor of random fluctuations (rapidly shaking of hands and fingers). We interpret these metaphors as the result of two kinds of representations elicited by sounds: auditory sensations (pitch and loudness) mapped to spatial position, and causal representations of the sound sources (e.g. rain drops, rustling leaves) pantomimed and embodied by the participants’ gestures.

Annoyance of low-level tonal sounds – Factors affecting the penalty

PurposeEnvironmental and appliance sounds involving tonal components can be more annoying than broad-band noise. Mandatory penalty values exist in many countries for tonal sound. The purpose of our study was to determine how tonal sounds are perceived compared to non-tonal sounds at overall levels close to typical regulated levels inside residential dwellings. MethodsForty participants rated the loudness and annoyance of tonal sounds and non-tonal reference sounds in laboratory conditions. The tonal frequencies were 50, 110, 290, 850 and 2100 Hz. Four levels of tonal audibility were used: 5, 10, 17 and 25 dB. The experiment was repeated using two overall levels of tonal sounds: 25 and 35 dB LAeq. Penalty was determined by finding an equally annoying reference sound. ResultsThe penalty depended on the tonal frequency and the tonal audibility. Penalty values were also different with different overall levels especially at high tonal frequencies. Annoyance penalty was zero at two lowest tonal frequencies 50 and 110 Hz. At other tonal frequencies, the penalty increased with increasing tonal audibility and tonal frequency. The largest value of penalty was 12 dB. It was obtained at tonal frequency 2100 Hz and with the largest level of tonal audibility. ConclusionsOur results are against the use of fixed penalty values, which are usual in many national regulations, when the overall level is low, within 25 and 35 dB LAeq. The results support the application of a step-wise penalty where the penalty depends on tonal frequency, tonal audibility and overall level.

Vocal Imitations of Non-Vocal Sounds.

Imitative behaviors are widespread in humans, in particular whenever two persons communicate and interact. Several tokens of spoken languages (onomatopoeias, ideophones, and phonesthemes) also display different degrees of iconicity between the sound of a word and what it refers to. Thus, it probably comes at no surprise that human speakers use a lot of imitative vocalizations and gestures when they communicate about sounds, as sounds are notably difficult to describe. What is more surprising is that vocal imitations of non-vocal everyday sounds (e.g. the sound of a car passing by) are in practice very effective: listeners identify sounds better with vocal imitations than with verbal descriptions, despite the fact that vocal imitations are inaccurate reproductions of a sound created by a particular mechanical system (e.g. a car driving by) through a different system (the voice apparatus). The present study investigated the semantic representations evoked by vocal imitations of sounds by experimentally quantifying how well listeners could match sounds to category labels. The experiment used three different types of sounds: recordings of easily identifiable sounds (sounds of human actions and manufactured products), human vocal imitations, and computational “auditory sketches” (created by algorithmic computations). The results show that performance with the best vocal imitations was similar to the best auditory sketches for most categories of sounds, and even to the referent sounds themselves in some cases. More detailed analyses showed that the acoustic distance between a vocal imitation and a referent sound is not sufficient to account for such performance. Analyses suggested that instead of trying to reproduce the referent sound as accurately as vocally possible, vocal imitations focus on a few important features, which depend on each particular sound category. These results offer perspectives for understanding how human listeners store and access long-term sound representations, and sets the stage for the development of human-computer interfaces based on vocalizations.

Interindividual differences in directional loudness

Sensibility of loudness to sound direction was measured in a two-intervals, 2AFC interleaved-adaptive procedure. We measured the level (at the center of the listener head) of a test sound matching the loudness of a reference fixed at 0° and 65 dB SPL (at the center of the listener head). Azimuths of the test sound varied from 0 to 180° by steps of 15°. Elevations were 15°, 30°, 45°, 60°, and 90°. Both test and reference sounds were wide-band noise. The difference between the levels of reference and test sounds at the point of loudness equality defined the Directional Loudness Sensibility (DLS). A group of 24 listeners showed up large differences in DLS. For the majority, the highest DLSs were around -4 dB. For a few of them DLSs were as large as -9 dB. Some listeners did not exhibit any DLS and could even achieve positive DLSs. The sound pressure levels, measured at the entrance of the ear canal, were related to the DLSs to see whether the interindividual differences in DLS were exclusively due to the filtering by the head or if extra-acoustics factors (such as binaural loudness constancy) might be involved in directional loudness sensitivity.

Vocal imitations of basic auditory features.

Describing complex sounds with words is a difficult task. In fact, previous studies have shown that vocal imitations of sounds are more effective than verbal descriptions [Lemaitre and Rocchesso (2014). J. Acoust. Soc. Am. 135, 862-873]. The current study investigated how vocal imitations of sounds enable their recognition by studying how two expert and two lay participants reproduced four basic auditory features: pitch, tempo, sharpness, and onset. It used 4 sets of 16 referent sounds (modulated narrowband noises and pure tones), based on 1 feature or crossing 2 of the 4 features. Dissimilarity rating experiments and multidimensional scaling analyses confirmed that listeners could accurately perceive the four features composing the four sets of referent sounds. The four participants recorded vocal imitations of the four sets of sounds. Analyses identified three strategies: (1) Vocal imitations of pitch and tempo reproduced faithfully the absolute value of the feature; (2) Vocal imitations of sharpness transposed the feature into the participants' registers; (3) Vocal imitations of onsets categorized the continuum of onset values into two discrete morphological profiles. Overall, these results highlight that vocal imitations do not simply mimic the referent sounds, but seek to emphasize the characteristic features of the referent sounds within the constraints of human vocal production.

Vocal imitations of basic auditory features

We recently showed that vocal imitations are effective descriptions of a variety of sounds (Lemaitre and Rocchesso, 2014). The current study investigated the mechanisms of effective vocal imitations by studying if speakers could accurately reproduce basic auditory features. It focused on four features: pitch, tempo (basic musical features), sharpness, and onset (basic dimensions of timbre). It used two sets of 16 referent sounds (modulated narrow-band noises and pure tones), each crossing two of the four features. Dissimilarity rating experiments and multidimensional scaling analyses confirmed that listeners could easily discriminate the 16 sounds based the four features. Two expert and two lay participants recorded vocal imitations of the 32 sounds. Individual analyses highlighted that participants could reproduce accurately pitch and tempo of the referent sounds (experts being more accurate). There were larger differences of strategy for sharpness and onset. Participants matched the sharpness of the referent sounds either to the frequency of one particular formant or to the overall spectral balance of their voice. Onsets were ignored or imitated with crescendos. Overall, these results show that speakers may not imitate accurately absolute dimensions of timbre, hence suggesting that other features (such as dynamic patterns) may be more effective for sound recognition.

On the effectiveness of vocal imitations and verbal descriptions of sounds.

Describing unidentified sounds with words is a frustrating task and vocally imitating them is often a convenient way to address the issue. This article reports on a study that compared the effectiveness of vocal imitations and verbalizations to communicate different referent sounds. The stimuli included mechanical and synthesized sounds and were selected on the basis of participants' confidence in identifying the cause of the sounds, ranging from easy-to-identify to unidentifiable sounds. The study used a selection of vocal imitations and verbalizations deemed adequate descriptions of the referent sounds. These descriptions were used in a nine-alternative forced-choice experiment: Participants listened to a description and picked one sound from a list of nine possible referent sounds. Results showed that recognition based on verbalizations was maximally effective when the referent sounds were identifiable. Recognition accuracy with verbalizations dropped when identifiability of the sounds decreased. Conversely, recognition accuracy with vocal imitations did not depend on the identifiability of the referent sounds and was as high as with the best verbalizations. This shows that vocal imitations are an effective means of representing and communicating sounds and suggests that they could be used in a number of applications.

Against ethnomusicology: Language performance and the social impact of ritual performance in Islam

Abstract This article argues that ‘music’ is unsatisfactory to reference sounds of ritual performance in Islam, not only because the term has been controversial for Muslims, but especially due to its unremovable pre-existing semantic load centred on non-referential aesthetic sound, resulting in drawing of arbitrary boundaries, incompatibility with local ontologies and under-emphasis on the referential language lying at the core of nearly all Islamic ritual. From the standpoint of the human sciences, this study is interested in the understanding of such rituals as combining metaphysical and social impact. Use of ‘music’ tends to distort and even preclude holistic ritual analysis capable of producing such understanding. As a result, ethnomusicology is misdirected. Theoretically and methodologically, this article develops an alternative concept, ‘language performance’ (LP), including four aspects – syntactic, semantic, sonic and pragmatic – especially designed for Islamic ritual performance. Applying a linguistic theory of communication developed by Jakobson, it shows how LP can be developed as a comprehensive, descriptive framework for comparative ritual analysis, akin to Lomax’s global Cantometrics, but avoiding its flaws through a more flexible design and modest scope, enabling systematic, comparative investigations of performance in Islamic ritual. The article closes with an example of such analysis centred on Sufi rituals in contemporary Egypt.

Vocal Imitations and the Identification of Sound Events

It is commonly observed that a speaker vocally imitates a sound that she or he intends to communicate to an interlocutor. We report on an experiment that examined the assumption that vocal imitations can effectively communicate a referent sound and that they do so by conveying the features necessary for the identification of the referent sound event. Participants were required to sort a set of vocal imitations of everyday sounds. The resulting clusters corresponded in most of the cases to the categories of the referent sound events, indicating that the imitations enabled the listeners to recover what was imitated. Furthermore, a binary decision tree analysis showed that a few characteristic acoustic features predicted the clusters. These features also predicted the classification of the referent sounds but did not generalize to the categorization of other sounds. This showed that, for the speaker, vocally imitating a sound consists of conveying the acoustic features important for recognition, within the constraints of human vocal production. As such vocal imitations prove to be a phenomenon potentially useful to study sound identification.

Comparison of subjective test methodologies for assessing human annoyance to low‐amplitude sonic booms.

In a subjective test assessing human annoyance to low‐amplitude sonic booms, different subjective testing methods were utilized. These included a hybrid categorical line scaling method as well as magnitude estimation with two different reference sounds. The test methods will be discussed, as well as their advantages and disadvantages. Other topics of discussion will include experimental design, data analysis, as well as subject participant preference. [Work sponsored by the NSF and the FAA through the PARTNER Center of Excellence.]

A new method for recognition of non‐voice sounds that is suitable for searching very large records.

An innovative non‐voice sound recognition system based on a new similarity scale called the geometric distance has been developed. It has been purpose‐designed for searching terabyte‐sized files for wildlife recordists. Initially this method has been used for analyzing continuous recordings of rare parrots in Australia. More recent work has extended its applications to other birds, bats, frogs, and marine animals. The software can search for multiple reference sounds and multiple species in a single pass. It has been demonstrated to achieve recognition accuracy comparable to a human expert.

Neural mechanisms involved in the oral representation of percussion music: An fMRI study

Numerous music cultures use nonsense syllables to represent percussive sounds. Covert reciting of these syllable sequences along with percussion music aids active listeners in keeping track of music. Owing to the acoustic dissimilarity between the representative syllables and the referent percussive sounds, associative learning is necessary for the oral representation of percussion music. We used functional magnetic resonance imaging (fMRI) to explore the neural processes underlying oral rehearsals of music. There were four music conditions in the experiment: (1) passive listening to unlearned percussion music, (2) active listening to learned percussion music, (3) active listening to the syllable representation of (2), and (4) active listening to learned melodic music. Our results specified two neural substrates of the association mechanisms involved in the oral representation of percussion music. First, information integration of heard sounds and the auditory consequences of subvocal rehearsals may engage the right planum temporale during active listening to percussion music. Second, mapping heard sounds to articulatory and laryngeal gestures may engage the left middle premotor cortex.

A computational model of rapid task-related plasticity of auditory cortical receptive fields

Receptive field properties of neurons in A1 can rapidly adapt their shapes during task performance in accord with specific task demands and salient sensory cues (Fritz et al., Hearing Research, 206:159-176, 2005a, Nature Neuroscience, 6: 1216-1223, 2003). Such modulatory changes selectively enhance overall cortical responsiveness to target (foreground) sounds and thus increase the likelihood of detection against the background of reference sounds. In this study, we develop a mathematical model to describe how enhancing discrimination between two arbitrary classes of sounds can lead to the observed receptive field changes in a variety of spectral and temporal discrimination tasks. Cortical receptive fields are modeled as filters that change their spectro-temporal tuning properties so as to respond best to the discriminatory acoustic features between foreground and background stimuli. We also illustrate how biologically plausible constraints on the spectro-temporal tuning of the receptive fields can be used to optimize the plasticity. Results of the model simulations are compared to published data from a variety of experimental paradigms.

Computer-Aided Technique for Automatic Determination of the Relationship between Transglottal Pressure Change and Voice Fundamental Frequency

The effect of artificially altered transglottal pressures on the voice fundamental frequency (F0) is known to be associated with vocal fold stiffness. Its measurement, though useful as a potential diagnostic tool for noncontact assessment of vocal fold stiffness, often requires manual and painstaking determination of an unstable F0 of voice. Here, we provide a computer-aided technique that enables one to carry out the determination easily and accurately. Human subjects vocalized in accordance with a series of reference sounds from a speaker controlled by a computer. Transglottal pressures were altered by means of a valve embedded in a mouthpiece. Time-varying vocal F0 was extracted, without manual procedures, from a specific range of the voice spectrum determined on the basis of the controlled reference sounds. The validity of the proposed technique was assessed for 11 healthy subjects. Fluctuating voice F0 was tracked automatically during experiments, providing the relationship between transglottal pressure change and F0 on the computer. The proposed technique overcomes the difficulty in automatic determination of the voice F0, which tends to be transient both in normal voice and in some types of pathological voice.