How much masking is informational masking?

Speech recognition in noisy environments improves when the speech signal is spatially separated from the interfering sound. This effect, known as spatial release from masking (SRM), was recently shown in young children. The present study compared SRM in children of ages 5-7 with adults for interferers introducing energetic, informational, and/or linguistic components. Three types of interferers were used: speech, reversed speech, and modulated white noise. Two female voices with different long-term spectra were also used. Speech reception thresholds (SRTs) were compared for: Quiet (target 0° front, no interferer), Front (target and interferer both 0° front), and Right (interferer 90° right, target 0° front). Children had higher SRTs and greater masking than adults. When spatial cues were not available, adults, but not children, were able to use differences in interferer type to separate the target from the interferer. Both children and adults showed SRM. Children, unlike adults, demonstrated large amounts of SRM for a time-reversed speech interferer. In conclusion, masking and SRM vary with the type of interfering sound, and this variation interacts with age; SRM may not depend on the spectral peculiarities of a particular type of voice when the target speech and interfering speech are different sex talkers.

Section: B Interferer-dependent Maskingmentioning

confidence: 92%

Effect of masker type and age on speech intelligibility and spatial release from masking in children and adults

Johnstone

Litovsky²

2006

“…This is a variation on the original account of non-additivity proposed by Green (1967). Lutfi's (1990) model provides an alternative account of additional masking but requires assumptions about changes in the proportion of informational masking across conditions that are difficult to justify.…”

Section: Discussionmentioning

confidence: 99%

“…Compression is not a possible contributor to this additional masking when the signal and/or one or more maskers overlap in time and in frequency because they are processed by the peripheral auditory system at the same time and place, and therefore, cannot be compressed independently. Lutfi (1990) has proposed a model of the additivity of masking that assumes that the effects of individual maskers are a result of both energetic and informational masking and that these effects add differently when maskers are combined. Energetic masking is assumed to add as energy, and informational masking is assumed to add in dB units approximating amounts of masking.…”

Section: Discussionmentioning

confidence: 99%

Nonadditivity of forward and simultaneous masking

Švec

Joshi

Jesteadt

2013

The current study measured the additional masking obtained for combinations of forward and simultaneous maskers as a function of forward masker bandwidth, signal delay, and simultaneous masker level. The effects of the two individual maskers were equated in all conditions. Additional masking increased with increasing masker level, increasing signal delay, and decreasing masker bandwidth. The portion of the simultaneous masker that made the greater contribution to additional masking was the part that overlapped with the signal, not with the forward masker. The changes in additional masking observed as a function of forward masker bandwidth and the interaction between the effects of forward and simultaneous maskers call into question the use of additional masking as a measure of basilar membrane compression and present problems for the use of simultaneous noise to simulate hearing loss.

“…However, hearing loss does impair a person's ability to benefit from signal/competitor separation. interference is known as 'informational masking" (Lufti, 1990;Pollack & Pickett, 1958) or "perceptual masking" (Carhart, Tillman, & Greetis, 1969a). To determine the contribution of the linguistic content to the masking effect, researchers have compared masking produced by speech competition to masking produced by nonsense speech or reversed speech.…”

Section: Binaural Processes For Speech Recognition In Noisementioning

confidence: 99%

Processing of speech in complex listening environments by individuals with obscure auditory dysfunction

Block

Gordon‐Salant

Hawley

et al. 2006

Obscure auditory dysfunction (OAD) is a disorder characterized by patient report of excessive amounts of difficulty understanding speech in the presence of background noise, despite relatively normal hearing sensitivity. It has been hypothesized that OAD may be the result of mild cochlear dysfunction, central auditory processing deficits, and/or psychological disorders. To evaluate auditory processing aspects of this disorder, speech recognition was measured in complex listening conditions for 10 normal-hearing persons with self-reported problems understanding speech in noisy environments. Ten normal-hearing listeners without reported difficulty hearing speech in noise served as controls. Each participant completed a standard audiometric evaluation, the QuickSIN test (standard clinical test of speech recognition in noise), and experimental speech recognition measures in simulated background environments, which included a range and combination of competitor stimuli presented in monaural and binaural conditions. The results show that the OAD participants had poorer overall speech recognition abilities in noise than did control participants for the experimental speech recognition tasks. The pattern of performance deficits suggests that the speech-understanding problems of these OAD participants are not attributable to abnormally poor binaural hearing or to a reduction in masking release. Further, performance deficits exhibited by listeners with OAD were not identified by a standard clinical speech-in-noise measure.