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...

When multiple microphones are available estimates of inter-channel delay, which characterise a speaker’s location, can be used as features for speaker diarization. Background noise and reverberation can, however, lead to noisy features and poor performance. To ameliorate these problems, this paper presents a new approach to the discriminant analysis of delay features for speaker diarization. Th...

This thesis explores compensation for reverberation in human listeners and machines. Late reverberation is typically understood as a distortion which degrades intelligibility. Recent research, however, shows that late reverberation is not always detrimental to human speech perception. At times, prolonged exposure to reverberation can provide a helpful acoustic context which improves identificat...

the polyphenol silybin has anti-oxidant and anti-cancer properties. the poor bioavailability of some polyphenols (flavonoids, and terpenoids) can be improved by binding them to phosphatidylcholine (phytosome technology). many studies have focused on the most common phytosome, silybin-phosphatidylcholine, particularly for its hepatoprotective effects. however, in recent years, studies have also ...

The Speech Transmission Index (STI) is based on acoustic measurements in environments and has been shown to be correlated with speech intelligibility under a wide range of acoustic conditions (Houtgast & Steeneken 1984). It is a weighted average of metrics derived from envelope signals in multiple frequency bands spanning the speech spectrum. A variety of methods have been proposed to compute t...