A new analysis of perceptual speech enhancement is presented. It focuses on the fact that if only noise above the masking threshold is filtered, then noise below the masking threshold, but above the absolute threshold of hearing, can become audible after the masker filtering. This particular drawback of some perceptual filters, hereafter called the maskee-to-audible-noise (MAN) phenomenon, favo...

The advent of diversity modulation and signal processing has changed the underlying assumption of the conventional collision model that at most one packet can be received at each node of a network. The use of antenna arrays, code division multiple access (CDMA), and space-time processing with multiuser detection makes multipacket reception (MPR) a more realistic model for the physical layer of ...

This is a sequel of our previous work [8] on characterization of maximum sum rate of slotted Aloha networks. By extending the analysis to incorporate the capacity-achieving receiver structure, Successive Interference Cancellation (SIC), this paper aims to identify the rate loss due to random access. Specifically, two representative SIC receivers are considered, i.e, ordered SIC where packets ar...

Over recent years we tested speech understanding and localization abilities of bilateral CI users with an extensive test battery [1, 2]. Figure 1, top panel, shows results of the speech test for seven bilateral CI users. Speech reception thresholds (SRTs) with speech and noise presented from the front were measured in the free-field. SRTs were between 0 and +6 dB, i.e. performance differed desp...

Matrix tests are available for speech recognition testing in many languages. For an accurate measurement, a steep psychometric function of the speech materials is required. For existing tests, it would be beneficial if it were possible to further optimize the available materials by increasing the function's steepness. The objective is to show if the steepness of the psychometric function of an ...

Background noise reduces the depth of the low-frequency envelope modulations known to be important for speech intelligibility. The relative strength of the target and masker envelope modulations can be quantified using a modulation signal-to-noise ratio, (S/N)(mod), measure. Such a measure can be used in noise-suppression algorithms to extract target-relevant modulations from the corrupted (tar...

When the acoustic signal is weak or disturbed, normal hearing people as well as hearing impaired make use of visual information as a support for their interpretation of the speech. Thus, a talking head could be of great support for the hearing impaired when engaged in speech activities where no visual information is available, such as a telephone conversation or when listening to an audio book....

In human hearing, frequency resolution is a term used to determine how well the ear can separate and distinguish two sounds that are close in frequency. This capability of breaking speech sounds into various frequency components plays a key role in processing and understanding speech information. In this paper, a piecewise-linear frequency shifting algorithm for digital hearing aids is proposed...