Manuj Yadav

Evaluation of stage acoustics preference for a singer using oral-binaural room impulse responses

There are two objective measurement methods in current practice that can be used to evaluate the stage acoustic conditions for singers. One is the stage support metrics (STEarly and STLate, included in the standard ISO 3389-1), and the other is the voice support metrics proposed by Brunskog et. al. and revised by Pelegrin-Garcia (room gain (GRG) and voice support (STV)). All of these metrics use energy integration from impulse responses to derive the acoustic descriptors. This overlooks two potentially important features of the responses: the temporal distribution of the impulse response within the evaluation period, and the directional distribution for the spatial impulse response within the evaluation period. In this paper, a method to study the effect of these features is proposed and tested. This method is based on the auralisation of ones′ own voice in rooms using oral-binaural room impulse responses (OBRIRs). The OBRIRs used are created by combining synthesized early reflections with a recorded reverberant tail. Results of a pilot study indicate that a wide range of on-stage acoustic quality ratings can be observed for stimuli with a similar STEarly value due to variation in the temporal and spatial distribution of reflected energy.

Autophonic Loudness of Singers in Simulated Room Acoustic Environments

OBJECTIVES This paper aims to study the effect of room acoustics and phonemes on the perception of loudness of ones own voice (autophonic loudness) for a group of trained singers. METHODS For a set of five phonemes, 20 singers vocalized over several autophonic loudness ratios, while maintaining pitch constancy over extreme voice levels, within five simulated rooms. RESULTS There were statistically significant differences in the slope of the autophonic loudness function (logarithm of autophonic loudness as a function of voice sound pressure level) for the five phonemes, with slopes ranging from 1.3 (/a:/) to 2.0 (/z/). There was no significant variation in the autophonic loudness function slopes with variations in room acoustics. The autophonic room response, which represents a systematic decrease in voice levels with increasing levels of room reflections, was also studied, with some evidence found in support. Overall, the average slope of the autophonic room response for the three corner vowels (/a:/, /i:/, and /u:/) was -1.4 for medium autophonic loudness. CONCLUSIONS The findings relating to the slope of the autophonic loudness function are in agreement with the findings of previous studies where the sensorimotor mechanisms in regulating voice were shown to be more important in the perception of autophonic loudness than hearing of room acoustics. However, the role of room acoustics, in terms of the autophonic room response, is shown to be more complicated, requiring further inquiry. Overall, it is shown that autophonic loudness grows at more than twice the rate of loudness growth for sounds created outside the human body.

Towards a method for loudness-based analysis of the sound of one's own voice

Abstract This paper outlines the steps in objectively estimating the time-varying loudness of ones own voice in a room (i.e. autophonic loudness). Voice recordings, made with a near-mouth microphone, are converted to the sound that reaches the two eardrums of the talking (or singing)-listener by convolving them with the impulse responses from the mouth to the respective ears of an anthropomorphic head and torso. The influences of bone-conducted sound and room reflections are taken into account. These convolved recordings are then processed with a computational time-varying loudness model. The method is demonstrated by a short case study, and the results illustrate something of the benefit of loudness analysis over sound pressure level analysis for representing autophonic loudness.

The irrelevant speech effect in multi-talker environments: Applications to open-plan offices

Irrelevant speech from co-workers has consistently been listed as one of the major nuisances within open-plan work environments. To explore the psychoacoustic basis of the so-called irrelevant speech effect (ISE; which causes cognitive decline and increases acoustic distraction) within a multi-talker context, a series of laboratory-based experiments were run. These experiments used room acoustical simulations of various open-plan office environments within a climate-controlled chamber to test several factors relevant to the ISE. These factors included the number of simultaneously active talkers, their spatial arrangements, sound pressure levels and the semanticity of speech. The main findings thus far indicate that multi-talker speech lead to a stronger ISE than speech from a single talker, which further interacts with the overall sound level, semanticity, etc., to exhibit a more complicated effect than what has been proposed in previous studies. The effect of the number of active talkers alone suggests r...

Workplace noise assessments by open-plan office occupants: Relationship with ISO 3382-3 metrics, and psychoacoustic parameters

ISO 3382-3:2012 is the international standard for measuring the acoustics of open-plan offices. These measurements are performed in unoccupied offices, and it has recently been shown that some of the ISO 3382-3 metrics, especially distraction distance, are useful in predicting the occupants’ perceived disturbance due to noise. The current research compares the ISO 3382-3 metrics, with several psychoacoustic parameters (loudness, fluctuation strength, etc.) derived from measurements done in an occupied state of open-plan offices, in terms of their usefulness in predicting occupants’ perception of several aspects of workplace noise. This comparison was based on using measurements performed in several offices in both occupied and unoccupied states, along with a workplace noise survey that was conducted in these offices. The results will enable a more comprehensive understanding of noise-related issues in open-plan offices, as it involves both physical acoustic, and psychoacoustic considerations.ISO 3382-3:2012 is the international standard for measuring the acoustics of open-plan offices. These measurements are performed in unoccupied offices, and it has recently been shown that some of the ISO 3382-3 metrics, especially distraction distance, are useful in predicting the occupants’ perceived disturbance due to noise. The current research compares the ISO 3382-3 metrics, with several psychoacoustic parameters (loudness, fluctuation strength, etc.) derived from measurements done in an occupied state of open-plan offices, in terms of their usefulness in predicting occupants’ perception of several aspects of workplace noise. This comparison was based on using measurements performed in several offices in both occupied and unoccupied states, along with a workplace noise survey that was conducted in these offices. The results will enable a more comprehensive understanding of noise-related issues in open-plan offices, as it involves both physical acoustic, and psychoacoustic considerations.

Experiments with high-back chairs and retroreflective surfaces for increasing the support of one’s own voice over short conversational distances

Acoustic support of one’s own voice affects speech, and increased support can foster more relaxed voice projection, which reverses the Lombard effect. While hearing one’s own voice in typical rooms shows subtle influences of “global” room acoustics, local treatment can yield stronger effects for talking-listeners. This paper considers two types of architectural acoustic treatment for supporting one’s own voice and modifying speech propagation—high-back chairs and retroreflective ceilings. For a talking-listener, local acoustic treatment such as high-back chairs can be designed to selectively attenuate ambient noise while providing enhanced reception of sound from a particular direction, project speech towards a listener with increased gain for speech intelligibility, and also provide voice support. Acoustically retroreflective surfaces (e.g., ceilings and vertical partitions) provide increased voice support by reflecting a person’s voice back to them, without such local treatment. This also has the advant...