Presence Of Background Sounds Research Articles

Investigating the effects of background noise and music on cognitive test performance in introverts and extraverts: A cross-cultural study

Previous research found that introverts performed worse than extraverts on cognitive tasks in the presence of noise or music in a Western sample but not in an Asian sample. This is a cross-cultural part replication of these studies using a Western (British; N = 45) and Asian (Singaporean; N = 45) sample. Participants engaged in three cognitive tests in the presence of pop songs, background noise, and in silence. It was predicted that for British participants, introverts would perform worse than extraverts on all three tasks in the presence of background sounds, and performance would be worse in the presence of background sounds than in silence, but not for the Singaporean participants. The results did not show any performance differences between the background sound conditions for any of the tests across the two samples, nor any performance differences between extraverts and introverts across the background sound conditions, with three exceptions: extraversion for the British was a significant predictor of performance on the Raven’s test in the silence condition, extraversion was a significant predictor of performance for both groups on the mental arithmetic task in the silence condition, and extraversion was a significant predictor of performance for Singaporeans on the mental arithmetic task in the music condition.

The computational prediction of masking thresholds for ecologically valid interference scenarios

Auditory interference scenarios, where a listener wishes to attend to some target audio while being presented with interfering audio, are prevalent in daily life. The goal of developing an accurate computational model which can predict masking thresholds for such scenarios is still incomplete. While some sophisticated, physiologically inspired, masking prediction models exist, they are rarely tested with ecologically valid programs (such as music and speech). In order to test the accuracy of model predictions human listener data is required. To that end a masking threshold experiment was conducted for a variety of target and interferer programs. The results were analyzed alongside predictions made by the computational auditory signal processing and prediction model described by Jepsen et al. (2008). Masking thresholds were predicted to within 3 dB root mean squared error with the greatest prediction inaccuracies occurring in the presence of speech. These results are comparable to those of the model by Glasberg and Moore (2005) for predicting the audibility of time-varying sounds in the presence of background sounds, which otherwise represent the most accurate predictions of this type in the literature.

2-Year-Olds' Speech Understanding in Multitalker Environments.

Infants and toddlers are often spoken to in the presence of background sounds, including speech from other talkers. Prior work has suggested that infants 1 year of age and younger can only recognize speech when it is louder than any distracters in the environment. The present study tests 24-month-olds' ability to understand speech in a multitalker environment. Children were presented with a preferential-looking task in which a target voice told them to find one of two objects. At the same time, multitalker babble was presented as a distracter, at one of four signal-to-noise ratios. Children showed some ability to understand speech and look at the appropriate referent at signal-to-noise ratios as low as -5 dB. These findings suggest that 24-month-olds are better able to selectively attend to an interesting voice in the context of competing distracter voices than are younger infants. There were significant correlations between individual children's performance and their vocabulary size, but only at one of the four noise levels; thus, it does not appear that vocabulary size is the driving factor in children's listening improvement, although it may be a contributing factor to performance in noisy environments.

Infants’ listening in multitalker environments: Effect of the number of background talkers

Infants are often spoken to in the presence of background sounds, including speech from other talkers. In the present study, we compared 5- and 8.5-month-olds' abilities to recognize their own names in the context of three different types of background speech: that of a single talker, multitalker babble, and that of a single talker played backward. Infants recognized their names at a 10-dB signal-to-noise ratio in the multiple-voice condition but not in the single-voice (nonreversed) condition, a pattern opposite to that of typical adult performance. Infants similarly failed to recognize their names when the background talker's voice was reversed--that is, unintelligible, but with speech-like acoustic properties. These data suggest that infants may have difficulty segregating the components of different speech streams when those streams are acoustically too similar. Alternatively, infants' attention may be drawn to the time-varying acoustic properties associated with a single talker's speech, causing difficulties when a single talker is the competing sound.

The effect on speech intelligibility of varying compression time constants in a digital hearing aid

The identification of nonsense syllables in quiet and in three types of background (babble, cafeteria and single female speaker) was measured using four hearing aid compression algorithms differing in attack and release time constants, and using linear amplification. The speech level was always 65 dB SPL. The compression algorithms, which were implemented in a Phonak Claro ITE hearing aid, were: (1) ‘very fast’—the attack time was 8 ms and the release time was 32 ms, for all 20 channels; (2) ‘slow–fast’—the attack and release times decreased from 500 ms for low frequencies to about 100 ms for high frequencies; (3) ‘fast–slow’—the attack and release times increased from about 50 ms for low frequencies to 500 ms for high frequencies; and (4) ‘slow+fast’—a very slow-acting gain control signal was combined with a fast-acting gain control signal, for each channel in a 10-channel system. Acoustical stimuli were presented monaurally via a circumaural headphone mounted over the hearing aid. The linear condition did not use the Claro aid; instead, the signal was digitally filtered to implement the Cambridge formula prior to delivery via the earphone. Five subjects with moderate sensorineural hearing loss were tested in a counter-balanced order across conditions. In quiet, performance was best for linear amplification and worst for the slow+fast algorithm. In the presence of background sounds, the highest scores were obtained with the linear-gain Cambridge formula implemented via headphones; a supplementary experiment suggested that this was due to the greater high-frequency gain resulting from the use of this formula. No significant differences were found between scores for the different compression algorithms. We conclude that the intelligibility of speech at a fixed level, presented in background sounds, is not markedly affected by rather substantial variations of the time constants in a multichannel compression system.

Speech processing for the hearing-impaired: successes, failures, and implications for speech mechanisms

People with sensorineural hearing impairment typically have more difficulty than normally hearing people in understanding speech in the presence of background sounds. This paper starts by quantifying the magnitude of the problem in various listening situations and with various types of background sound. It then considers some of the factors that contribute to this difficulty, including: reduced audibility; reduced frequency selectivity; loudness recruitment; and regions in the cochlea which have no surviving inner hair cells and/or neurones (dead regions). Methods of compensating for the effects of some of these factors are described and evaluated. Signal-processing methods to compensate for the effects of reduced frequency selectivity using the output of a single microphone have had only limited success, although methods using multiple microphones have worked well. Amplitude compression can compensate for some of the effects of loudness recruitment, allowing speech to be understood over a wide range of sound levels. The exact form of the compression (fast-acting versus slow-acting, single-channel versus multiple channel) does not seem to be critical, suggesting that the relative loudness of different components of speech, and dynamic aspects of loudness perception do not need to be restored to “normal”.