Voice source characteristics in six premier country singers

Voice source characteristics as derived from inverse filtering were analyzed in 6 country singers' speech and singing. Results showed that the closed quotient varied systematically with vocal loudness, and that glottal compliance (the ratio between transglottal AC volume displacement and subglottal pressure) decreased with increases in fundamental frequency but remained unaffected by vocal loudness. No striking differences were found in source characteristics between speech and singing within subjects. The degree of phonatory press, as judged by a panel of 19 expert listeners, appeared related to the range in which the singer was singing and to the sound pressure level gain from a doubling of subglottal pressure.     

Intensity range as a function of task and training

This study examined intensity range as a function of elicitation task (reading and automatic speech sequences), musical training, and the interaction between task and musical training in 31 college students. The results indicated significant differences in loudness range by experiental task. Intensity range for the descending automatic sequence was significantly greater than that for the ascending and reading tasks. While the overall effect of musical training was nonsignificant, there was a significant interaction between task and training, with musicians having a significantly greater mean range on the ascending task. A comparison between ascending and descending tasks indicated a significant mean difference between lower limits and no significant mean difference between upper limits. The range for the reading probe was located approximately in the middle of the total available intensity range.     

Moore响度计算模型的改进

与早期响度的图表计算方法相比,Moore计算模型是基于解析式的并且实现了响度值随频率、强度改变的连续计算,因此使用起来非常方便;然而,Moore模型计算公式中基本参数值的确定所依据的闻阈标准数据已被修订,并且最新研究表明,Moore模型在确定α值时所做的假设是不合理的;因此本文中(1)提出了利用耳蜗输入输出函数以确定响度函数的方法;(2)根据多个频率处的响度函数重新估计了Moore模型的参数α;(3)根据最新的闻阈标准数据和新的机理重新修订了其它基本参数;(4)利用新的模型重新计算了等响曲线并与原有模型的结果以及最新国际标准进行了对比。结论表明对1～8kHz之间的计算结果有了较大的修订,特别是能很好地预测1～2kHz之间的凸起。     

A-weighted sound pressure level as a loudness/annoyance indicator for environmental sounds - Could it be improved?

A system is introduced with the purpose of showing how an auditory perception system may be built up to include the basic quantities on loudness domain. The quantities are the critical bands, the power law, and the weighting. The power law seems to be the most crucial basis for hypothesizing a loudness function. It has been shown that the power law could be applied as such by assuming the auditory perception system to have two essentially different stimuli: the intensity (sound pressure level) and pure pressure. These physically different quantities seem to be combined in the root of the power law, and in this study the roots are determined from equal-loudness contours. A loudness function is derived on the basis of this finding. By adding the weighting, a method has been constructed for assessing loudness. After defining the weighting, the equal-loudness contours are constructed and are seen to be virtually identical to the contours in ISO 226. It has also been found that the equations for deriving the contours in this standard and in the new ISO 226 may be incorrect, because there is no definition of a sensible loudness function. Finally, it is deduced that the derived weighting must be unequivocal for an auditory perception system (depending solely on the otologically representative group). Finally, the A-weighting (as part of an A-weighted sound pressure level) as such is reasonably similar to the weighting derived in this study. Therefore, this weighting is not the main problem when assessing sounds in respect to loudness. The A-weighting is thus chosen as the weighting for the indicator derived in the study for assessing environmental sounds.     

Effect of listening level and background noise on the subjective decay rate of room impulse responses: Using time-varying loudness to model reverberance

Room impulse responses (RIRs) are used very widely to characterize the acoustic conditions of rooms, such as in the derivation of reverberation time, early decay time and clarity index. This study investigates the subjective decay rate (or reverberance) of RIRs when directly listened to (rather than convolved with a dry signal such as speech or music). Through a subjective experiment, it investigates the effects of gain (or listening level) and background noise level on the reverberance of RIRs that had been measured in three concert auditoria. The task of the experiment was to match the decay rate of RIRs to that of a reference RIR by ear, by adjusting the RIRs’ exponential decay rate. Based on objective loudness modeling, gain should have a positive effect on reverberance, and background noise has a negative effect. This is confirmed in the results of the experiment. Furthermore, the objectively calculated loudness decay function provides an effective predictor of subjective decay rate, which performs better than conventional early decay time or reverberation time for the RIRs tested.     

Relationships between arithmetic averages of sound pressure level calculated in octave bands and Zwicker’s loudness level

Previously it has been found through a series of psychoacoustical experiments that the arithmetic average of sound pressure level calculated in octave bands is a good estimator of loudness for various kinds of environmental noise. Remarkably, the arithmetic average of sound pressure level in octave bands from 63 Hz to 4 kHz, L_m,1/1(63-4k), strongly correlates with the loudness level specified in ISO 532B, LL(Z), as well as with loudness assessment. To investigate this relationship further, a numerical study has been carried out based on Zwicker’s loudness model. As a result, practical expressions to estimate the loudness levels of general environmental noises from the sound pressure levels in octave bands from 63 Hz or 125 Hz to 4 kHz are proposed.     

Effects of perceived listeners on speakers''vocal intensity

The purpose of this study was to determine the amount of change in speakers' vocal intensity when a listener is located at various perceived versus actual physical distances from a speaker. Twelve men and 12 women with normal voices were asked to read a passage at three interspeaker distances in one of two conditions. In the perceived listener condition, participants were asked to “imagine” that the listener was located 3, 15, or 30 ft away. In the actual listener condition, one of the experimenters stood at each one of the three experimental distances. Conditions were counterbalanced. The results showed that men and women increased vocal intensity levels for all three interspeaker distances regardless of the type of condition. However, women showed larger increases than men at all interspeaker distances in both conditions. Data for both men and women combined showed that the amount of increase is <6 dB, which indicates that speakers do not follow the inverse square law when raising vocal intensity. Clinical implications of the results are discussed.     

Loudness criteria in auditorium acoustics

I.IntroductionLoudnessisoneofthedistinguishingcharactcristicsamonga1lacousticcriteriainauditori-umdesign.Insufficientorsevcrcunevendistributionofloudncsscausesseriousdeficiencytoauditoriumacoustics.Duetothelackofappropriateparamcter,thereisnowayeithertopre-dictloudnessinanauditoriumduringthedcsignstagc,ortochccktheactua1effectafterthecomp1etionoftheconstruction.Wca1lmighthavethcexpcricnccasanaudiencethatthestagcattractedmoreofourcon-ccntrationduringthesoftpassagcofthcpcrformance,whercaswewcre…     

An experimental study on loudness evaluation of early reflections

I.IntroductionLoudnessisoncofthedistinguishingcharacteristicsinauditoriumacoustics,buthasreceivedlessattentionthanotherparametersinthepast.Genera11ytheresu1tingloudness,orthetotalenergylevelofasteadysoundsourceinahallcanbesimplypredictedbythesumofthedircctsoundandthcreverberantsound.Asspeechandmusic,areoftransicntcharacteristics,theperceivedloudnessinahallismorecomplicatedandthustheaboveprc-dichonisnottrue.Accordingtotheintegratingabilityoftheear,onlythcdirectsoundandthecarlyreflections,i.c.,…