In reverberant environments, acoustic reflections interfere with the direct sound arriving at a listener's ears, distorting the binaural cues for sound localization. We investigated the effects of reverberation on the directional sensitivity of single neurons in the inferior colliculus (IC) of unanesthetized rabbits. We find that reverberation degrades the directional sensitivity of single neur...

By varying the sound-absorption treatments in a simulated classroom, experimental results were compared with analytical and computer predictions of reverberation time. Analytical predictions were made with different absorption exponents, which are the result of different weighting procedures involving room surface areas and the sound-absorption coefficients. Sound scattering was found to influe...

Little is known about the extent to which reverberation affects speech intelligibility by cochlear implant (CI) listeners. Experiment 1 assessed CI users' performance using Institute of Electrical and Electronics Engineers (IEEE) sentences corrupted with varying degrees of reverberation. Reverberation times of 0.30, 0.60, 0.80, and 1.0 s were used. Results indicated that for all subjects tested...

The Tonal and Speech Materials for Auditory Perceptual Assessment, Disc 1.0 audio compact disc developed in 1992 includes several sets of degraded speech materials, two of which, time compression and reverberation, are described in this paper. The digital techniques used to compress the NU No. 6 materials (female speaker) on an 80386-based computer are described, along with a series of experime...

Reverberation caused by sound re ected o surfaces and objects is present in abundance in everyday life. Yet, in most situations we are unaware of it. This is due to the ability of our auditory system to adapt to the incoming sound re ections, which results in increased echo thresholds, i.e. the minimum delay to hear a re ection as an echo is increased after the echo was heard repeatedly. Change...

At high frequencies, interaural time differences (ITDs) are conveyed by the sound envelope. Sensitivity to envelope ITDs depends crucially on the envelope shape. Reverberation degrades the envelope shape, reducing the modulation depth of the envelope and the slope of its flanks. Reverberation also reduces the envelope interaural coherence (i.e., the similarity of the envelopes at two ears). The...

This paper proposes a framework for spectral enhancement of reverberant speech based on inversion of the modulation transfer function. All-pole modeling of modulation spectra of clean and degraded speech are utilized to derive the linear prediction inverse modulation transfer function (LP-IMTF) solution as a low-order IIR filter in the modulation envelope domain. By considering spectral estimat...

Speech intelligibility in reverberant environments is reduced because of overlap-masking. Signal modification prior to presentation in such listening environments, e.g., with a public announcement system, can be employed to alleviate this problem. Time-scale modifications are particularly effective in reducing the effect of overlap-masking. A method for introducing linguistically-motivated paus...

This paper presents a method for blind estimation of reverberation times in reverberant enclosures. The proposed algorithm is based on a statistical model of short-term log-energy sequences for echo-free speech. Given a speech utterance recorded in a reverberant room, it computes a Maximum Likelihood estimate of the room full-band reverberation time. The estimation method is shown to require li...