China
Africa
Explore chapters and articles related to this topic
Hearing Aids for the Pediatric Population
Published in Stavros Hatzopoulos, Andrea Ciorba, Mark Krumm, Advances in Audiology and Hearing Science, 2020
Katia de Almeida, Maria Cecíli Martinelli
Directional microphones can substantially improve the signal-to-noise ratio and audibility. However, for children, the use of hearing aids with directional microphones does not seem to be as advantageous as in adults, because these microphones attenuate sounds coming from behind and the sides. This may affect the audibility of sounds from certain directions, limiting directional hearing, and incidental learning (AAA, 2013). This may be one of the reasons why hearing aids fixed directionality mode is not recommended for children despite the advantages widely documented in adults to improve the signal/noise ratio (Kuk, 1999). Hearing aids with automatic shifting between omnidirectional and directional modes can be considered. Small but significant additional directional benefits may be associated with adaptive directional microphone technology and no significant negative consequences are associated with adaptive directional processing in adult listeners. However, it is the responsibility of the audiologist to understand the switching parameters of the automatic program, as well as the acoustic conditions of the educational setting, to establish appropriate expectations for any automatic switching behavior. In some cases, full-time omnidirectional mode may be referred to an automatic directional mode.
Case 32
Published in Simon Lloyd, Manohar Bance, Jayesh Doshi, ENT Medicine and Surgery, 2018
Simon Lloyd, Manohar Bance, Jayesh Doshi
Transfer of sound from the side of a dead ear to the functioning contralateral ear. In this role BAHDs act in a similar way to a CROS aid. It allows individuals with a dead ear to hear sounds more effectively on the ipsilateral side through transcranial transmission to the contralateral ear. Whilst this is helpful to some extent, it does not actually restore hearing in the affected ear and therefore does not restore directional hearing or improve the ability to hear in a noisy environment, 2 situations in which those with unilateral hearing loss struggle.
Binaural and spatial hearing
Published in Stanley A. Gelfand, Hearing, 2017
Another aspect of directional hearing involves determining the smallest difference in location between two sound sources that results in a different perceived location. Since the two sound sources are viewed relative to the head, this is the same as asking what is the smallest angle (or difference in azimuth) that a listener can discriminate. Mills (1958, 1963, 1972) studied this phenomenon in depth, and called it the minimal audible angle (MAA). Specifically, he tested the MAA as a function of frequency when the sound sources were located in front of the subject (0°), and when they were 30°, 45°, 60°, and 75° off to the side. The logistics of the basic task are illustrated in Figure 13.12, where we see that the listener must distinguish the difference between two points in space. Notice that the figure actually shows two different conditions, one in which the MAA is being determined when both sound sources are directly in front of the listener (at 0° azimuth) and another one in which the two sound sources are off to one side (at 45° azimuth).
Cochlear implant indications: a review of third-party payers’ policies for standard and expanded indications
Published in Cochlear Implants International, 2021
Lindsey E. Moses, David R. Friedmann
Outside of the criteria described above, there are many patients who suffer from hearing loss that could derive significant benefit from a CI but experience difficulty obtaining insurance approval. These include patients with single sided deafness,6,7 hearing loss secondary to meningitis,8,9 and those with residual low-frequency acoustic hearing but poor speech understanding hindering oral communication.10,11 A patient with severe to profound hearing loss who receives one CI may also experience difficulty obtaining approval for a second CI despite the known benefits of binaural hearing.12,13 Evidence for the success of cochlear implants for patients with these indications has been widely published, but the expansion of criteria by the FDA and insurance providers is slow and variable. For example, a study of audiologic performance in 20 patients in Germany with SSD who received CI showed significant improvement in directional hearing and speech perception in noise with use of the CI.14 Improved hearing in noise and music appreciation has been shown with use of electro-acoustic stimulation in patients with residual low-frequency hearing.10,15 Notably FDA approval of the Cochlear Hybrid-L cochlear implant was granted for adults age 18 and over in 2014. More recently the FDA approved the MED-EL cochlear implant system for patients 5 years and older with single-sided deafness, a new indication which has since been adopted by some, but not the majority of third-party payers.16
Adults with unilateral congenital ear canal atresia – sound localization ability and recognition of speech in competing speech in unaided condition
Published in Acta Oto-Laryngologica, 2021
Malin Siegbahn, Cecilia Engmér Berglin, Malou Hultcrantz, Filip Asp
Binaural cues are crucial for the ability to localize sound accurately in the horizontal plane. Binaural listeners use interaural differences in sound pressure level and time as cues to localize sound in the horizontal plane, and these cues also facilitate speech recognition in background noise [2]. Binaural processing is believed to develop during the first five years of life in normal hearing subjects [3]. It is well established that horizontal sound localization ability is negatively affected by both sensorineural- and conductive unilateral hearing loss. Localization ability differs between individuals; Rosenhall [4] found that the degree of unilateral sensorineural hearing loss (>40 dB) was an important factor in directional hearing, when sound was presented at a comfortable level. Some patients with unilateral conductive hearing loss perform surprisingly well in a localization task in unaided conditions [5]. However, the variability in performance is poorly understood.
Speech perception 30 years after cisplatin-based chemotherapy in adults: limited clinical relevance of long-term ototoxicity?
Published in Acta Oncologica, 2021
J. Skalleberg, M. Myhrum, M. C. Småstuen, T. A. Osnes, S. D. Fosså, M. Bunne
Importantly, some Cases had quite poor HINT scores both in noise and quiet, indicating that individual patients may experience severe problems with speech perception. Cases had slightly, but statistically significant worse HINT scores with speech from front and noise from either side. This slight difference is likely due to the worse high-frequency thresholds among Cases, leading to a poorer sound localization and Spatial Release from Masking (SRM). SRM refers to the ability to utilize that speech and noise come from different directions. An important part of SRM is the head-shadow effect: with HINT NR/NL the sound reaches each ear at slightly different times and volumes. The brain uses these differences to localize the sound and to hear in background noise. The effect of a difference in volume is most pronounced in the higher frequencies because the shorter wavelengths of high-frequency sounds are more blocked by the human head than those of lower frequencies [45]. Hence, directional hearing and hearing in noise may be slightly poorer among TCS, for example identifying what is said from whom and where in a noisy environment.