¡@¡@Taiwan is surrounded by sea, there are coral reefs at both south and north ends, and also at off-shore islands. Coral reef offers habitat and resources for marine animals, that are attracted to in numbers, however due to the limited resources, competitions and conflicts are common among animals. In order to defend the territory on intimidate intruder, some fishes develop vocal mechanism that certain sounds are generated at encounter. The sounds of common Holocendridae fishes at coral reef were studied before, but the sound characteristics of sound were not fully investigated. In this research, sound samples were recorded from Neoniphon sammara, Myripristis murdjan, and Sargocentron spinosissimum(Holocentridae) in an indoor water tank, to understand more about their specific features of sounds generated at disturbance. The identification system of this study was based on Matlab, which extracted the characteristic parameters from the sounds, so the database for comparison can be formed. The sounds can be classified into single pulse and pulse train, and the parameters used are dominant frequency, band width, duration, and pulse repetition rate. As the result, Neoniphon sammara has single pulse frequency of 428.0¡Ó95.0 Hz (mean ¡Ó standard deviation), pulse train frequency of 449.8¡Ó92.4 Hz, Myripristis murdjan has single pulse and pulse train frequency of 375.2¡Ó96.3 Hz and 369.2¡Ó96.0 Hz, and Sargocentron spinosissimum has single pulse and pulse train frequency of 377.6¡Ó93.5 Hz and 387.8¡Ó97.1 Hz. The similarity of sounds between Neoniphon sammara and Myripristis murdjan is 81.3%, between Myripristis murdjan and Sargocentron spinosissimum is 83.6%, and between Neoniphon sammara and Sargocentron spinosissimum is 90.3%. Finally, the identification accuracy of Neoniphon sammara is 78.9%, Myripristis murdjan is 71.4%, and Sargocentron spinosissimum is 38.4%. The low identification accuracy of Sargocentron spinosissimum is due to the high similarity of sounds with Myripristis murdjan, and the number of sound samples is not sufficient.

This thesis studied the effects of ear training on motivation and the ability to identify sounds under a layer of pink noise, using two versions of a training application. The first version was a serious game that utilized common game design features with the aim of increasing the player’s motivation to keep playing. The second version, called the basic training application was used as a base-line and modeled after the training method used by Shafiro (2008) in his experiment #2. 14 participants (divided into two groups of 7) were tested on their ability to identify sounds and how motivated they felt to continue training. Results pointed to the basic training application being better at increasing the participants’ sound identification ability, and the serious game being better at retaining the participants’ motivation to keep playing. Future studies should aim to combine features from both versions of the training application.

Hearing protectors are used in noisy environments to attenuate damaging soundlevels. Problems are reported to arise from using hearing protectors, since usefulsounds also are attenuated. Not only are sound levels attenuated, but other humanabilities are affected by hearing protectors, such as the ability to identify and localizesounds. Manufacturers of hearing protectors also develop level-dependent hearingprotectors that are supposed to create a better listening experience for the user thandoes passive hearing protectors. This thesis investigates how the ability to identifysound is affected by hearing protectors in the Swedish processing industry and towhat extent level-dependent hearing protectors improve the user’s ability to identifysound. Semi-structured interviews were conducted by asking questions based on theprojects research questions and theories found from a literary study. A questionnairewas sent out with similar questions for verification purposes. The current literatureshows that the human ability to identify sound deteriorates by the occlusion from hearing protectors. Indications are such that hearing protectors with a level-dependent function deteriorate the ability less than does passive protectors. The relevance of this in the processing industry does not seem to be very palpable. Usersindicate that it would be dangerous for this ability to be deteriorated in theworkplace and that level-dependent hearing protectors does a better job apreserving sound identification than passive protectors, but their soundidentification ability is not deteriorated enough by passive hearing protectors forproblems to arise.

No description available.

Noise pollution is widespread in today’s society, from traffic to industrial sources, and many people are confined to unhealthy acoustic environments through their employment. When noise cannot be eliminated at the sound source, the protective measure is usually to equip the employee with hearing protection devices (HPDs), e.g. earmuffs, that attenuates the noise. Applying excessive attenuation can render the wearer disconnected from her acoustic environment and present risks and social isolation. HPDs using level-dependent function (LDF) uses ambient microphones together with a signal processing unit and internal loudspeakers to achieve attenuation flexibility – if ambient noise is low, the loudspeakers can amplify the sound to combat an excessive passive attenuation of the HPD, and if ambient noise is high this amplification is decreased to maintain healthy sound levels. Appropriate levels of attenuation allows the user to detect ambient sounds which contributes to the their situational awareness. Besides attenuating the sounds however, HPDs does change the spectral content of the sound which may complicate the ability to identify them. This thesis has focused on exploring the human ability to identify sounds, design a method for measuring this ability, implement it and evaluate its result and the method itself. The thesis has been conducted in collaboration with 3MTM PeltorTM and was intended to evaluate the effect of earmuffs with LDF on the ability to identify sounds in a process industry soundscape. The progression of the thesis was structured within the Double Diamond process, where literature reviews, benchmarking and workshops informed the research and resulted in a method design that was analyzed using a repeated measures ANOVA based on empirical data from 16 participants. Surprisingly, the results showed no statistically significant advantage from wearing a HPD using LDF, as opposed to no LDF, in the user accuracy or certainty in sound identification. The reasons for this are discussed with a focus on evaluating the usefulness of the designed method in future efforts to develop HPDs that afford reliable sound identification. / Bullerföroreningar är ett utbrett problem i dagens samhälle, från trafik till industriella källor, och många människor är låsta till en ohälsosam akustisk miljö via sin anställning. När buller inte kan elimineras vid ljudkällan är skyddsåtgärden vanligtvis att förse arbetstagaren med hörselskydd, exempelvis hörselkåpor, som dämpar bullret. Att använda en överdriven dämpning kan dock göra att användaren avskiljs helt från sin akustiska miljö och innebära risker samt social isolering. Hörselskydd utrustade med nivåberoende funktion (LDF) använder mikrofoner tillsammans med en signalbehandlingsenhet och interna högtalare för att uppnå flexibilitet i dämpningen – om omgivande buller är lågt kan högtalarna förstärka ljudet för att motverka en överdriven passiv dämpning erbjuden av hörselskyddet, om omgivande buller däremot är högt kan denna förstärkning minskas för att vidhålla sunda ljudnivåer. Lämpliga dämpningsnivåer gör att användaren kan upptäcka omgivande ljud som bidrar till deras situationsmedvetenhet. Förutom att dämpa ljuden så ändrar dock hörselskydd också det spektrala innehållet i ljudet vilket kan komplicera förmågan att identifiera ljuden. Denna masteruppsats har fokuserat på att utforska människans förmåga att identifiera ljud, utforma en metod för att mäta denna förmåga, implementera metoden och utvärdera dess resultat samt metoden i sig. Uppsatsen har genomförts i samarbete med 3MTM PeltorTM och var avsedd att utvärdera effekten av hörselkåpor, utrustade med LDF, på förmågan att identifiera ljud i ett ljudlandskap likt det i en processindustri. Projektet var strukturerad enligt Double Diamondprocessen, där litteraturstudier, benchmarking och workshops har informerat och väglett arbetet och resulterat i en metod som analyserats med hjälp av variansanalys baserat på empiriska data från 16 deltagare. Överraskande nog så visade resultaten ingen statistiskt signifikant fördel med att bära ett hörselskydd som är utrustat med LDF till skillnad från ett hörselskydd som saknar denna funktion, vad gäller användarens förmåga att korrekt identifiera ljud samt rapporterad säkerhet i svaren. Orsaker till detta diskuteras med fokus på att utvärdera användbarheten av den utformade metoden i framtida ansträngningar för att utveckla hörselskydd som erbjuder tillförlitlig ljudidentifiering.

No description available.