How reliable are online speech intelligibility studies with known listener cohorts?

Although the use of nontraditional settings for speech perception experiments is growing, there have been few controlled comparisons of online and laboratory modalities in the context of speech intelligibility. The current study compares outcomes from three web-based replications of recent laboratory studies involving distorted, masked, filtered, and enhanced speech, amounting to 40 separate conditions. Rather than relying on unrestricted crowdsourcing, this study made use of participants from the population that would normally volunteer to take part physically in laboratory experiments.

Sculpting speech from noise, music, and other sources.

Intelligible speech can be generated by passing a signal through a time-frequency mask that selects which information to retain, even when the signal is speech-shaped noise, suggesting an important role for the mask pattern itself. The current study examined the relationship between the signal and the mask by varying the availability of target speech cues in the signal while holding the mask constant. Keyword identification rates in everyday sentences varied from near-ceiling to near-floor levels as the signal was varied, indicating that the interaction between the signal and mask, rather than the mask alone, determines intelligibility.

Non-native consonant acquisition in noise: Effects of exposure/test similarity.

When faced with speech in noise, do listeners rely on robust cues or can they make use of joint speech-plus-noise patterns based on prior experience? Recent studies have suggested that listeners are better able to identify words in noise if they experienced the same word-in-noise tokens in an earlier exposure phase. The current study examines the role of token similarity in exposure and test conditions. In three experiments, Spanish learners of English were exposed to intervocalic consonants during an extensive training phase, bracketed by pre- and post-tests.

Lexical frequency effects in English and Spanish word misperceptions.

When listeners misperceive words in noise, do they report words that are more common? Lexical frequency differences between misperceived and target words in English and Spanish were examined for five masker types. Misperceptions had a higher lexical frequency in the presence of pure energetic maskers, but frequency effects were reduced or absent for informational maskers. The tendency to report more common words increased with the degree of energetic masking, suggesting that uncertainty about segment identity provides a role for lexical frequency.

Effects of exposure to noise during perceptual training of non-native language sounds.

Listeners manage to acquire the sounds of their native language in spite of experiencing a range of acoustic conditions during acquisition, including the presence of noise. Is the same true for non-native sound acquisition? This study investigates whether the presence of masking noise during consonant training is a barrier to improvement, or, conversely, whether noise can be beneficial. Spanish learners identified English consonants with and without noise, before and after undergoing one of four extensive training regimes in which they were exposed to either consonants or vowels in the presence or absence of speech-shaped noise.

A corpus of noise-induced word misperceptions for English.

Words spoken against a noise background often form an ambiguous percept. However, in certain conditions, a listener will mishear a noisy word but report hearing the same incorrect word as reported by other listeners. These consistent hearing errors are valuable as tests of detailed models of speech perception.

A corpus of noise-induced word misperceptions for Spanish.

Word misperceptions are valuable in designing and evaluating detailed computational models of speech perception, especially when a number of listeners agree on the misperceived word. The current paper describes the elicitation of a corpus of Spanish word misperceptions induced by different types of noise. Stimuli were presented using an adaptive procedure designed to promote the rapid discovery of misperceptions.

The effect of speech modification on non-native listeners for matrix-style sentences.

Speech can be modified to promote intelligibility in noise, but the potential benefits for non-native listeners are difficult to predict due to the additional presence of distortion introduced by speech alteration. The current study compared native and non-native listeners' keyword scores for simple sentences, unmodified and with six forms of modification. Both groups showed similar patterns of intelligibility change across conditions, with the native cohort benefiting slightly more in stationary noise.

The Sharvard Corpus: a phonemically-balanced Spanish sentence resource for audiology.

Objective: The current study describes the collection of a new phonemically-balanced Spanish sentence resource, known as the Sharvard Corpus.

Design: The resource contains 700 sentences inspired by the original English Harvard sentences along with speech recordings from a male and female native peninsular Spanish talker. Sentences each contain five keywords for scoring and are grouped into 70 lists of 10 sentences using an automatic phoneme-balancing procedure.

The intelligibility of Lombard speech for non-native listeners.

Speech produced in the presence of noise--Lombard speech--is more intelligible in noise than speech produced in quiet, but the origin of this advantage is poorly understood. Some of the benefit appears to arise from auditory factors such as energetic masking release, but a role for linguistic enhancements similar to those exhibited in clear speech is possible. The current study examined the effect of Lombard speech in noise and in quiet for Spanish learners of English.

Consonant identification in noise by native and non-native listeners: effects of local context.

Speech recognition in noise is harder in second (L2) than first languages (L1). This could be because noise disrupts speech processing more in L2 than L1, or because L1 listeners recover better though disruption is equivalent. Two similar prior studies produced discrepant results: Equivalent noise effects for L1 and L2 (Dutch) listeners, versus larger effects for L2 (Spanish) than L1.