Speech perception in noise:Masking and unmasking

Speech perception is essential for daily communication.Background noise or concurrent talkers,on the other hand,can make it challenging for listeners to track the target speech(i.e.,cocktail party problem).The present study reviews and compares existing findings on speech perception and unmasking in cocktail party listening environments in English and Mandarin Chinese.The review starts with an introduction section followed by related concepts of auditory masking.The next two sections review factors that release speech perception from masking in English and Mandarin Chinese,respectively.The last section presents an overall summary of the findings with comparisons between the two languages.Future research directions with respect to the difference in literature on the reviewed topic between the two languages are also discussed.

Single-channel speech enhancement method based on masking properties and minimum statistics

A single-channel speech enhancement method of noisy speech signals at very low signal-to-noise ratios is presented, which is based on masking properties of the human auditory system and power spectral density estimation of non stationary noise. It allows for an automatic adaptation in time and frequency of the parametric enhancement system, and finds the best tradeoff among the amount of noise reduction, the speech distortion, and the level of musical residual noise based on a criterion correlated with perception and SNR. This leads to a significant reduction of the unnatural structure of the residual noise. The results with several noise types show that the enhanced speech is more pleasant to a human listener.

Changes in call properties of Boana pulchella (Anura, Hylidae) in response to different noise conditions

The increasing expansion of urban areas leads to the emergence of new noisy environments that can affect animal communication.Calls play a crucial role in the mating displays of anurans,and the negative impact of anthropogenic noise-induced auditory masking has been reported in several species.We investigated the acoustic variation in 96 males(n=971 calls)of the treefrog Boana pulchella across acoustically undis-turbed sites and different noise conditions,associated with urban areas(URBAN)and roads(ROAD),in Central Argentina.We analyzed the effect of anthropogenic noise conditions on 6 temporal(call duration[CD],intercall interval,first and second note duration,internote interval,and call rate)and 3 spectral(dominant frequency of first and second note,frequency difference between them)call properties.The effects of temperature and size on acoustical variables were controlled.We observed differences in all call attributes among the noise conditions,except for intercall interval.Males exposed to URBAN and ROAD exhibited significant changes in CD,dominant frequency of the second note,and fre-quency difference between them.URBAN males had longest internote interval,while ROAD individuals displayed increased first and second note duration and call rates.Interestingly,ROAD males exhibited immediate changes in call rate in direct response to passing heavy vehicles.Our study emphasizes the impact of anthropogenic noise on the acoustic characteristics of B.pulchella calls.Understanding how animals adapt to noisy environments is crucial in mitigating the adverse effects of urbanization on their communication systems.Future investigations should explore whether the observed call adjustments are effective in avoiding or mitigating the negative consequences of anthropogenic noise on reproductive success.