Handclap for Acoustic Measurements: Optimal Application and Limitations

Abstract

Handclap is a convenient and useful acoustic source. This study aimed to explore its optimal application and limitations for acoustic measurements as well for other possible utilizations. For this purpose, the following steps were performed: investigation of the optimal hand configuration for acoustic measurements and measurements at different microphone source distances and at different spaces and positions. All measurements were performed with a handclap and a dodecahedron speaker for comparison. The results indicate that the optimal hand configuration (among 11) is with the hands cupped and held at an angle due to the superior low frequency spectrum. This configuration produced usable acoustic parameter measurements in the low frequency range in common room background levels unlike other configurations. The reverberation time was measured across different spaces and positions with a deviation less than three and just a noticeable difference of the signal-to-noise ratio within or near the ISO 3382-1 limits for each corresponding octave band. Other acoustic parameters (i.e., early decay time, clarity) were measured with greater deviations for reasons discussed in the text. Finally, practical steps for measurements with a handclap as an acoustic source are suggested.

Numerical assessment of ultrasound supported coalescence of water droplets in crude oil

“…The acoustic criteria was selected as with second order element. This criterion is essential for accurate prediction of the ultrasound propagation [54] , [55] , [56] , [57] , [58] . Although the acoustic criteria provide reasonable estimation for the ultrasound, the predictions for the laminar flow was inadequate.…”

Sound Reflections in Indian Stepwells: Modelling Acoustically Retroreflective Architecture

“…Experience with other retroreflective environments is varied. In some, handclaps are effective, even though a typical clap has an approximately pink power spectrum [34,35] (whereas a white or high-frequency-dominated spectrum would be preferable). Clapping is most likely to be effective when there is an audibly significant time delay for the retroreflection cluster arrival.…”

Improved Source Characteristics of a Handclap for Acoustic Measurements: Utilization of a Leather Glove

“…A study on the sound generation of a handclap [12] has shown that a shock wave can be created with the addition of a Helmholtz-type resonance in the case of domed impacts. Eleven different clapping modes according to hand configuration have been identified [13], while additional variations may derive from such factors as hand curvature, stiffness, fleshiness of the palms, tightness of the fingers, precision, and striking force [14].…”

“…On the subject of repeatability, the handclap may have one of the lowest performance among acoustic sources, the reason being that variations of hand configuration may alter the generated impulse and spectral characteristics, and also there is considerable variability in the spectral shapes of handclaps across individuals [14]. On the subject of frequency response, studies [13,14] measured different hand configurations and found in general that a roll-off is evident below 500 Hz for all of them. However, domed hand configurations have a subsidiary maximum that is caused by Helmholtz resonance, which results in an increased level in the low frequency range.…”

“…Regarding measurements of acoustic parameters, all the studies found in the literature where the handclap was used as an acoustic source [13,[16][17][18][19] showed that results for the low frequency range were unreliable. However in [13], reverberation time was measured across different spaces and positions, with a deviation of less than 3 JND (just-noticeable difference) for signal to noise ratio, and within or near the ISO 3382-1 limits for each corresponding octave band. In the same study, other acoustic parameters (early decay time, clarity) were measured with greater deviations.…”