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Publications (10 of 80) Show all publications
Johansson, Ö., Pamidi, T. R. & Löfqvist, T. (2017). Design of a high-intensity ultrasound reactor. In: : . Paper presented at 2017 IEEE International Ultrasonics Symposium (IUS),Washington, DC, 6-9 Sept. 2017. Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Design of a high-intensity ultrasound reactor
2017 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Design, and optimization of ultrasonic reactors are important objectives in sonochemical processing. The recent expansion of the use of ultrasonic reactors in various research areas all faces the problem of scaling up from laboratory results to industrial purposes. A traditional ultrasonic reactor usually has several issues, such as low effectiveness as well as complex and unstable system performance, which all are unfavorable for efficient sonochemical processing. This study addresses these issues and investigates a new flow type ultrasonic reactor designed to generate transient cavitation as the main source for ultrasound. Some important factors like pressure, material, flow and geometry are considered in the design. Numerical optimization as well as experimental investigations are performed to reach an optimized, energy-efficient and controlled ultrasound cavitation reactor. Results from numerical modeling are used for acoustic optimization of the reactor, which is driven with three transducers mounted radially in the reactor wall with 120° spacing. The final reactor is excited with dual frequencies a total of 9 sonotrodes. The reactor is intended to be used in studies of pre-treatment of cellulose fibers aiming at developing an alternative, energy efficient fibrillation process and for ultrasound leaching of minerals.

Place, publisher, year, edition, pages
Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017
National Category
Fluid Mechanics and Acoustics Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Engineering Acoustics; Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-66534 (URN)10.1109/ULTSYM.2017.8092948 (DOI)978-1-5386-3383-0 (ISBN)
Conference
2017 IEEE International Ultrasonics Symposium (IUS),Washington, DC, 6-9 Sept. 2017
Available from: 2017-11-09 Created: 2017-11-09 Last updated: 2017-11-24Bibliographically approved
Johansson, Ö., Pamidi, T. R. & Löfqvist, T. (2017). Design of a high-intensity ultrasound reactor. In: IEEE International Ultrasonics Symposium, IUS: . Paper presented at 2017 IEEE International Ultrasonics Symposium (IUS), Washington, DC, 6-9 Sept. 2017. Piscataway, NJ: IEEE Computer Society, Article ID 8091660.
Open this publication in new window or tab >>Design of a high-intensity ultrasound reactor
2017 (English)In: IEEE International Ultrasonics Symposium, IUS, Piscataway, NJ: IEEE Computer Society, 2017, article id 8091660Conference paper, Published paper (Refereed)
Abstract [en]

Design, and optimization of ultrasonic reactors are important objectives in sonochemical processing. The recent expansion of the use of ultrasonic reactors in various research areas all faces the problem of scaling up from laboratory results to industrial purposes. A traditional ultrasonic reactor usually has several issues, such as low effectiveness as well as complex and unstable system performance, which all are unfavorable for efficient sonochemical processing. This study addresses these issues and investigates a new flow type ultrasonic reactor designed to generate transient cavitation as the main source for ultrasound. Some important factors like pressure, material, flow and geometry are considered in the design. Numerical optimization as well as experimental investigations are performed to reach an optimized, energy-efficient and controlled ultrasound cavitation reactor. Results from numerical modeling are used for acoustic optimization of the reactor, which is driven with three transducers mounted radially in the reactor wall with 120° spacing. The final reactor is excited with dual frequencies a total of 9 sonotrodes. The reactor is intended to be used in studies of pre-treatment of cellulose fibers aiming at developing an alternative, energy efficient fibrillation process and for ultrasound leaching of minerals

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE Computer Society, 2017
Series
IEEE International Ultrasonics Symposium, E-ISSN 1948-5719
National Category
Fluid Mechanics and Acoustics Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Engineering Acoustics; Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-66533 (URN)10.1109/ULTSYM.2017.8091660 (DOI)000416948400055 ()2-s2.0-85039413569 (Scopus ID)978-1-5386-3383-0 (ISBN)
Conference
2017 IEEE International Ultrasonics Symposium (IUS), Washington, DC, 6-9 Sept. 2017
Available from: 2017-11-09 Created: 2017-11-09 Last updated: 2018-01-16Bibliographically approved
Johansson, Ö., Löfqvist, T. & Pamidi, T. R. (2017). Design of high-intensity ultrasound reactor. In: IEEE International Ultrasonics Symposium, IUS: . Paper presented at 2017 IEEE International Ultrasonics Symposium (IUS), Washington, DC, 6-9 Sept. 2017. Piscataway, NJ: IEEE Computer Society, Article ID 8092948.
Open this publication in new window or tab >>Design of high-intensity ultrasound reactor
2017 (English)In: IEEE International Ultrasonics Symposium, IUS, Piscataway, NJ: IEEE Computer Society, 2017, article id 8092948Conference paper, Published paper (Refereed)
Abstract [en]

Design and optmiziation of ultrasonic reactors are important objectives in sonochemical processing. The recent expansion of the use of ultrasonic reactors in various research projects all faces the problem of scaling up laboratory results for industrial use. A traditional ultrasonic reactor usually has several issues, such as low effectiveness and complex and unstable system performance, which all are unfavorable for efficient sonochemical processing. This study adresses these issues and investigates a new flow type ultrasonic reactor designed to generate transient cavitation as the main source for ultrasound for sonochemical processing. This study proposes the principle of the flow type ultrasonic reactor design to generate transient cavitation. The objective of this work is to design an ultrasonic reactor with a new geometry. The idea is to improve process efficiency based on resonance enhanced ultrasound controlled cavitation

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE Computer Society, 2017
Series
IEEE International Ultrasonics Symposium, ISSN 1948-5719
National Category
Fluid Mechanics and Acoustics Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Engineering Acoustics; Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-67244 (URN)10.1109/ULTSYM.2017.8092948 (DOI)000416948403005 ()2-s2.0-85039437533 (Scopus ID)978-1-5386-3383-0 (ISBN)
Conference
2017 IEEE International Ultrasonics Symposium (IUS), Washington, DC, 6-9 Sept. 2017
Available from: 2018-01-11 Created: 2018-01-11 Last updated: 2018-01-16Bibliographically approved
Johansson, Ö., Pamidi, T., Khoshkhoo, M. & Sandström, Å. (2017). Sustainable and energy efficient leaching of tungsten(W) by ultrasound controlled cavitation. Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Sustainable and energy efficient leaching of tungsten(W) by ultrasound controlled cavitation
2017 (English)Report (Other academic)
Abstract [en]

The project aims to use ultrasound controlled cavitation to achieve a more energy efficient leaching process. Locally, collapsing cavitation bubbles cause an extremely high pressure, shock waves and high temperature, which provide an opportunity to perform the leaching process at a much lower temperature than in an autoclave (20 bar overpressure and 220 ° C). The results show that the method works, but that a higher static pressure and thus temperatures are necessary to achieve a leaching recovery rate corresponding to today's autoclave technology. Another process parameter of importance is flow control and the initiation of cavitation bubbles that occur through a geometrically optimized nozzle (orifice plate). Numerical and experimental adaptation of the developed reactor with respect to the leaching conditions (Sodium hydroxide and Scheelite concentrate), required more time than expected. Best test results show that an energy supplement with ultrasonic controlled cavitation of 104 kWh / kg increases the leaching recovery by 21%. The leaching reagent temperature 60° C was determined regarding available reference data and was thought to be close to optimum for intensive cavitation in atmospheric pressure. Optimum temperature relates to the leaching reagent, vaporization temperature, density, boiling point, surface tension, and viscosity. Generally, for leaching is that higher temperatures are required to increase the chemical reaction rate (requires overpressure). The modified reactor principle provides stable results and is possible to scale up. Higher cavitation intensity for shorter finishing time and higher recovery rate require advanced flow induction, multiple excitation frequencies adapted to the optimized reactor geometry, as well as optimal process pressure and temperature.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2017. p. 20
Series
Research report / Luleå University of Technology, ISSN 1402-1528
Keywords
Ultrasound, Cavitation; Leaching, Scheelite, Vibro acoustic optimization
National Category
Mineral and Mine Engineering Fluid Mechanics and Acoustics Metallurgy and Metallic Materials
Research subject
Engineering Acoustics; Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-66286 (URN)978-91-7790-160-0 (ISBN)
Projects
Vinnova SIP-Strim
Funder
VINNOVA, 2016-02620VINNOVA
Available from: 2017-10-27 Created: 2017-10-27 Last updated: 2018-06-05Bibliographically approved
Wijaya, A. R. & Johansson, Ö. (2016). Difference thresholds of multi-axis whole-body vibration. In: IEEE International Conference on Industrial Engineering and Engineering Management: . Paper presented at 2016 International Conference on Industrial Engineering and Engineering Management, IEEM 2016, Bali, Indonesia,4-7 December 2016 (pp. 1760-1764). Piscataway, NJ: IEEE Computer Society, Article ID 7798180.
Open this publication in new window or tab >>Difference thresholds of multi-axis whole-body vibration
2016 (English)In: IEEE International Conference on Industrial Engineering and Engineering Management, Piscataway, NJ: IEEE Computer Society, 2016, p. 1760-1764, article id 7798180Conference paper, Published paper (Refereed)
Abstract [en]

A laboratory study was conducted to investigate the effects of lateral and horizontal vibration on the difference threshold of vertical vibration. Twelve male subjects sat on a rigid seat and were exposed to four different vibration conditions (pure vertical vibration; combination of horizontal and vertical vibration; combination of lateral and vertical vibration; combination of horizontal, lateral and vertical vibration). Vertical vibration for four conditions was 5 Hz sinusoidal with a magnitude of 1 ms-2 r.m.s. Horizontal and lateral vibration for the last three conditions were sinusoidal with magnitude 0.5 ms-2 r.m.s. and contained ten frequencies (1 to 8 Hz in third-octave band step). The frequency-weighted acceleration of the ten frequencies was equal. Results showed that horizontal and lateral vibrations have different effects on the difference threshold of vertical vibration. The combination of vertical and horizontal vibration gave a significantly lower difference threshold of vertical vibration than the combination of vertical and lateral vibration

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE Computer Society, 2016
Series
IEEE International Conference on Industrial Engineering and Engineering Management, ISSN 2157-3611
National Category
Fluid Mechanics and Acoustics
Research subject
Engineering Acoustics
Identifiers
urn:nbn:se:ltu:diva-61851 (URN)10.1109/IEEM.2016.7798180 (DOI)000392208100357 ()2-s2.0-85009874493 (Scopus ID)9781509036653 (ISBN)
Conference
2016 International Conference on Industrial Engineering and Engineering Management, IEEM 2016, Bali, Indonesia,4-7 December 2016
Available from: 2017-02-07 Created: 2017-02-07 Last updated: 2017-11-24Bibliographically approved
Johansson, Ö. (2016). Energieffektivisering genom flödesexciterad, resonansförstärkt och ultraljudskontrollerad kavitation: Delprojekt inom Mekmassainitiativet för energieffektivitet (E2MPi) (ed.). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Energieffektivisering genom flödesexciterad, resonansförstärkt och ultraljudskontrollerad kavitation: Delprojekt inom Mekmassainitiativet för energieffektivitet (E2MPi)
2016 (Swedish)Report (Other academic)
Abstract [sv]

Projektet syftar till att öka kunskap och förståelse för hur kavitation kan användas och kontrolleras för att koncentrera bearbetningsenergin till frekvensområden som ger effektiv påverkan av cellulosafibrer. Tanken är att skapa ett komplement eller en alternativ teknik till dagens raffinörer. Idén bygger på att resonansförstärkt ultraljud initierar och kollapsar kavitationsbubblor på ytan av cellulosafibrer i vatten. Tidigare forskning har visat att ultraljudsbehandling ger önskade effekter på fiberväggen. Energieffektiviteten har dock inte varit tillräckligt bra och uppskalning är en identifierad problematik. Den föreslagna metoden syftar till att via numerisk och experimentell optimering åstadkomma en energieffektiv och kontrollerad bearbetning av fiberväggen. Den långsiktiga målsättningen är att halvera energiförbrukningen i jämförelse med dagens raffinörer.Hypotesen är att ultraljudskontrollerad kavitation fungerar beroende på att transient asymmetrisk kollapsa av kavitationsbubblor kan ge upphov till extrema tryck på en liten yta. Principen bygger på små att gasbubblor i vatten exciteras av högintensivt ultraljud. Vid en viss kritisk storlek kommer bubblan i resonans och då växer den snabbt. Yttre trycket når sitt max i samband med att bubblan kollapsar. Ultraljud med konstant frekvens (ex 20 kHz) gör att mängder av bubblor, med varierande storlek och harmoniskt relaterade resonansfrekvenser, kollapsar. De jetstrålar i mikroskala som uppstår vid asymmetrisk kollaps av kavitationsbubblor antas ge en mekanisk påverkan av cellulosafibrer i form av både inre och yttre fibrillering.Projektet har resulterat i en utveckling och verifiering av en FE-baserad optimeringsstrategi för flödesinducerad och ultraljudskontrollerad kavitation. Den framtagna kavitationsreaktorn består av en dysa och ett vattenfyllt reaktorrör exciterat med ultraljud. Fibersuspensionen strömmar genom ett inre tunnväggigt rör i reaktorns centrum. Beräkningsmodellen ger stabila resultat avseende ultraljudsexcitering och är kalibrerad med experimentellt bestämda förlustfaktorer för aktuell prototypreaktor. Simuleringar av flödesinducerad kavitation begränsades till ren vattenfas. Den framtagna geometrin är dock verifierad avseende strömning med fibersuspension. Experimentella resultat utan flöde visar mycket god överenstämmelse avseende beräknade svängningsformer och resonansfrekvenser. Beräknad ljudtrycksnivå är högre än uppmätt beroende på de olinjäriteter som uppstår när vätskan utsätts för mycket höga amplituder. Dessutom är förlustfaktorn något högre i experimenten och trycksignalens verkliga effektinnehåll ligger delvis utanför mätområdet.Beräkningsjämförelser med ett alternativt och kommersiellt förekommande reaktorkoncept (behållare), visar att den nyutvecklade rörreaktorn ger högre intensitet i den optimala zonen (+120%). Den totala förlustfaktorn för rörreaktorn är ca 1.1 % vid resonans. Tillförd elektrisk effekt bestäms genom att mäta ström och spänning när kavitationsreaktorn exciteras vid sin resonansfrekvens. Optimal kavitationseffekt identifieras av ljudtrycksamplitudkvoten: pUS(f1.5)/pUS(f1). Kavitation ger effektiv bearbetning av fibermaterialet i zonen för maximal tryckvariation. Initiering av flödesinducerad kavitation med justerbar Venturi-dysa ger intensivare kavitation samt god blandning och sammanhållen fibersuspension. Test och verifiering med fibermaterial är baserad på en HT-CTMP fiber (torkad/aldrig torkad) med 0.5%, 1% och 2% konc. Positiv förändring av fiberkvalitet uppstod endast i några av testfallen. I test med både flödesinducerad och ultraljudsstyrd kavitation uppstod bäst resultat vid lägst energinivå (470 kWh/adt). I övriga testfall finns misstanke om att fibermaterialet har förstörts av för hög kavitationsintensitet. En slutsats som delvis verifieras av SEM-analys av behandlat fibermaterial. Tillförd energinivå var dock inte tillräcklig för att uppnå godkänd massakvalitet, dvs. lika bra eller bättre dragindex. I nuläget går det inte att fastställa om föreslagen metod är energieffektiv på grund av svårigheten i att jämföra en prototyp och fullskaleanläggning. En uppenbar förbättringsmöjlighet med framtagen reaktorlösningen är att förlänga reaktorröret (ej realiserbart i prototypskedet). Den valda reaktorlösningen kan skalas upp genom parallellkoppling och seriekoppling. Seriekoppling och längre reaktorrör kräver ett högre matningstryck vilket kan ge en fördel med högre kavitationsintensitet. Den experimentella valideringen är begränsad till en excitationsfrekvens (22.7 kHz) och normaltryck. En kombination med högre ultraljudsfrekvenser (37 och/eller 53 kHz för rörreaktorn) är en möjlig förbättring genom att de aktiva bubblornas storlek reduceras och får en storleksordning som är bättre anpassad till fiberväggens storlek och struktur. En annan förbättringsaspekt är ett högre statiskt tryck, vilket ökar kavitationsintensiteten och möjliggör en förkortad exponeringstid.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2016. p. 49
Series
Research report / Luleå University of Technology, ISSN 1402-1528
Keywords
Forestry, agricultural sciences and landscape planning - Wood fibre and forest products, Engineering mechanics - Other engineering mechanics, Ultrasound structural acoustics resonance cavitation hydro dynamic, Acoustics, optimizatin, Skogs- och jordbruksvetenskap samt landskapsplanering - Träfiber- och virkeslära, Teknisk mekanik - Övrig teknisk mekanik
National Category
Fluid Mechanics and Acoustics
Research subject
Engineering Acoustics
Identifiers
urn:nbn:se:ltu:diva-23714 (URN)81e643ab-e6f8-482b-9bee-8470bdd309ba (Local ID)978-91-7583-645-4 (ISBN)81e643ab-e6f8-482b-9bee-8470bdd309ba (Archive number)81e643ab-e6f8-482b-9bee-8470bdd309ba (OAI)
Note
Godkänd; 2016; 20160608 (orjo)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Nykänen, A., Johnsson, R., Sirkka, A. & Johansson, Ö. (2013). Assessment of changes in preference ratings of auralized engine sounds caused by changes in frequency resolution of transfer functions (ed.). Paper presented at . Applied Acoustics, 74(12), 1343-1353
Open this publication in new window or tab >>Assessment of changes in preference ratings of auralized engine sounds caused by changes in frequency resolution of transfer functions
2013 (English)In: Applied Acoustics, ISSN 0003-682X, E-ISSN 1872-910X, Vol. 74, no 12, p. 1343-1353Article in journal (Refereed) Published
Abstract [en]

Auralization facilitates aural examination of contributions from different sound sources, individually and as parts of a context. Auralizations can be created by filtering sounds of perceptually salient sources through binaural transfer functions (BTFs) from source positions to a listening position. When such auralizations are used for product sound design it is essential to know that they are of sufficient quality. A basic requirement is that preference ratings are unaffected by the quality of the auralizations. The objective of this study was to measure changes in preference ratings of auralized engine sounds caused by changes in frequency resolution of used BTFs. Auralizations of engine sounds were created by filtering source sounds through BTFs measured from source positions to a driver’s position inside a truck cabin. The BTFs were altered by lowering the frequency resolution and by smoothing in the frequency domain. Preferences for the auralizations were compared using a modified version of the MUlti Stimulus test with Hidden Reference and Anchor, MUSHRA (ITU-R BS.1534-1). Since the use of a reference is only appropriate when a reference known to be most preferred exists the reference was removed, resulting in a MUlti Stimulus Test with Hidden Anchors (MUSTHA). For assessment of the differences between the auralizations a statistical method commonly used for assessing agreement between methods of clinical measurement was adopted. The lowest frequency resolutions resulting in acceptable agreement between preference ratings of auralizations made with high frequency resolution (1 Hz) BTFs and auralizations made with simplified BTFs were 32 Hz frequency resolution or smoothing with either 1/24 octave bandwidth filters or 63 Hz absolute bandwidth filters.

National Category
Fluid Mechanics and Acoustics
Research subject
Engineering Acoustics
Identifiers
urn:nbn:se:ltu:diva-9325 (URN)10.1016/j.apacoust.2013.05.005 (DOI)000324227100005 ()2-s2.0-84879340090 (Scopus ID)7ecb64fe-34ba-46dd-82f7-60bfe2d531b4 (Local ID)7ecb64fe-34ba-46dd-82f7-60bfe2d531b4 (Archive number)7ecb64fe-34ba-46dd-82f7-60bfe2d531b4 (OAI)
Note
Validerad; 2013; 20130626 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Wigholm, P., Nilsson, P.-Å. & Johansson, Ö. (2013). Best avaliable technology: Buller från bergtäkter (ed.). Paper presented at . København: Nordisk ministerråd
Open this publication in new window or tab >>Best avaliable technology: Buller från bergtäkter
2013 (Swedish)Report (Other (popular science, discussion, etc.))
Abstract [sv]

På uppdrag av Nordiska ministerrådet har ÅFs experter inom ljud och vibrationer utvärderat bästa tillgängliga teknik (BAT-Best Available Technique) avseende buller från bergtäkter. Syftet är att visa hur bullerutbredningen kan variera från en bergtäkt beroende på val av maskinutrustning och tillämpning av bästa möjliga teknik. Riktvärden, villkor och mätmetoder är relativt lika i de Nordiska länderna, men skillnader finns. Analysen fokuserar på de ljudeffekter som olika maskiner och verksamheter ger upphov till, samt vad som normalt görs och kan beaktas i en bergtäkt för att minska bullerspridning till omgivningen. Resultatet visar att med tillämpning av bästa tillgängliga teknik (BAT) kan ljudutbredningen till omgivningen minskas betydligt. Avståndet från täkt till punkt i omgivningen där riktvärdet överskrids kan då halveras jämfört med den bullrigaste situationen. Detta innebär att området som överstiger riktvärdet, med rätt topografiska förutsättningar och tillämpning av BAT, kan minskas ned till en fjärdedel.

Place, publisher, year, edition, pages
København: Nordisk ministerråd, 2013. p. 60
Series
TemaNord, ISSN 0908-6692 ; 2013:588
National Category
Fluid Mechanics and Acoustics
Research subject
Engineering Acoustics
Identifiers
urn:nbn:se:ltu:diva-24454 (URN)10.6027/TN2013-588 (DOI)b0936ce6-ab82-40b0-95d1-87ec74e0a471 (Local ID)978-92-893-2662-9 (ISBN)b0936ce6-ab82-40b0-95d1-87ec74e0a471 (Archive number)b0936ce6-ab82-40b0-95d1-87ec74e0a471 (OAI)
Note
Upprättat; 2013; 20141006 (orjo)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Johansson, Ö., Schönfeld, S. & Lindforss, D. (2012). Sound sketch procedure for auralization of the interior sound of a high speed train (ed.). In: (Ed.), Courtney Burroughs (Ed.), Proceedings of Inter-Noise 2012: held in conjunction with the annual meeting of the Noise Control and Acoustics Division of the American Society of Mechanical Engineers ; New York, New York, USA, August 19 - 22, 2012. Paper presented at International Congress and Exposition on Noise Control Engineering : 19/08/2012 - 22/08/2012. Washington, DC: International institute of noise control engineering
Open this publication in new window or tab >>Sound sketch procedure for auralization of the interior sound of a high speed train
2012 (English)In: Proceedings of Inter-Noise 2012: held in conjunction with the annual meeting of the Noise Control and Acoustics Division of the American Society of Mechanical Engineers ; New York, New York, USA, August 19 - 22, 2012 / [ed] Courtney Burroughs, Washington, DC: International institute of noise control engineering , 2012Conference paper, Published paper (Other academic)
Place, publisher, year, edition, pages
Washington, DC: International institute of noise control engineering, 2012
National Category
Fluid Mechanics and Acoustics
Research subject
Engineering Acoustics
Identifiers
urn:nbn:se:ltu:diva-33966 (URN)80e0d15e-70fd-4418-b980-03e02c9727ce (Local ID)80e0d15e-70fd-4418-b980-03e02c9727ce (Archive number)80e0d15e-70fd-4418-b980-03e02c9727ce (OAI)
Conference
International Congress and Exposition on Noise Control Engineering : 19/08/2012 - 22/08/2012
Note
Godkänd; 2012; 20140929 (orjo)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Nykänen, A., Johnsson, R., Sirkka, A. & Johansson, Ö. (2011). Assessment of the change in similarity judgements of auralized engine sounds caused by changes in frequency resolution of transfer functions (ed.). Paper presented at . Applied Acoustics, 72(2-3), 115-123
Open this publication in new window or tab >>Assessment of the change in similarity judgements of auralized engine sounds caused by changes in frequency resolution of transfer functions
2011 (English)In: Applied Acoustics, ISSN 0003-682X, E-ISSN 1872-910X, Vol. 72, no 2-3, p. 115-123Article in journal (Refereed) Published
Abstract [en]

Auralization facilitates aural examination of contributions from different sound sources, individually and as parts of a context. Auralizations can be created by filtering sounds of the perceptually most salient sources through binaural transfer functions (BTFs) from source positions to a listening position. When psychoacoustic analysis is based on auralizations, the auralizations need to give the same impression as real sounds. The objective of this study was to determine the frequency resolution required for auralizations to be perceptually equivalent to recordings made with an artificial head. Auralizations of the contribution of engine sounds to interior sounds of a truck were examined. In listening tests auralizations based on simplified BTFs were compared to artificial head recordings. The BTFs were simplified by lowering the frequency resolution and by smoothing in the frequency domain. Auralizations made through BTFs with a resolution of 4 Hz or higher or smoothed with maximum 1/96 octave moving average filters were perceived as similar to artificial head recordings.

National Category
Fluid Mechanics and Acoustics
Research subject
Engineering Acoustics
Identifiers
urn:nbn:se:ltu:diva-10947 (URN)10.1016/j.apacoust.2010.10.007 (DOI)000285812200006 ()2-s2.0-78649465128 (Scopus ID)9d723c90-f335-11df-8b36-000ea68e967b (Local ID)9d723c90-f335-11df-8b36-000ea68e967b (Archive number)9d723c90-f335-11df-8b36-000ea68e967b (OAI)
Note
Validerad; 2011; 20101118 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-2955-2776

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