Subject: [AUDITORY] Bioacoustics paper in Current Biology From: Natasha Mhatre <natasha@xxxxxxxx> Date: Mon, 30 Sep 2013 09:33:59 +0200 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>--047d7bdc11cc0ca87104e794dcda Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Dear all, We just published a paper on a cochlear amplifier like mechanism in the tympanal auditory system of a cricket. The paper is open access. Apologies for cross posting. A Tympanal Insect Ear Exploits a Critical Oscillator for Active Amplification and Tuning Natasha Mhatre & Daniel Robert http://www.cell.com/current-biology/abstract/S0960-9822(13)01034-8 *Highlights* - The tympanal ears of a tree cricket use active amplification - Active amplification and not passive resonance determines tuning to song frequency - Active amplification and tuning have an =93on=94 and an =93off=94 stat= e - Crickets are the phylogenetically oldest insects with active auditory amplification *Summary* A dominant theme of acoustic communication is the partitioning of acoustic space into exclusive, species-specific niches to enable efficient information transfer. In insects, acoustic niche partitioning is achieved through auditory frequency filtering, brought about by the mechanical properties of their ears [1]. The tuning of the antennal ears of mosquitoes [2] and flies [3], however, arises from active amplification, a process similar to that at work in the mammalian cochlea [4]. Yet, the presence of active amplification in the other type of insect ears=97tympanal ears=97has remained uncertain [5]. Here we demonstrate the presence of active amplification and adaptive tuning in the tympanal ear of a phylogenetically basal insect, a tree cricket. We also show that the tree cricket exploits critical oscillator-like mechanics, enabling high auditory sensitivity and tuning to conspecific songs. These findings imply that sophisticated auditory mechanisms may have appeared even earlier in the evolution of hearing and acoustic communication than currently appreciated. Our findings also raise the possibility that frequency discrimination and directional hearing in tympanal systems may rely on physiological nonlinearities, in addition to mechanical properties, effectively lifting some of the physical constraints placed on insects by their small size [6] and prompting an extensive reexamination of invertebrate audition Best wishes, Natasha --047d7bdc11cc0ca87104e794dcda Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr">Dear all,<div><br></div><div>We just published a paper on = a cochlear amplifier like mechanism in the tympanal auditory system of a cr= icket. The paper is open access. Apologies for cross posting.</div><div><br= > </div><div>A Tympanal Insect Ear Exploits a Critical Oscillator for Active = Amplification and Tuning</div><div>Natasha Mhatre & Daniel Robert</div>= <div><a href=3D"http://www.cell.com/current-biology/abstract/S0960-9822(13)= 01034-8">http://www.cell.com/current-biology/abstract/S0960-9822(13)01034-8= </a><br> </div><div><br></div><div><div><b>Highlights</b></div><div><ul><li>The tymp= anal ears of a tree cricket use active amplification<br></li><li>Active amp= lification and not passive resonance determines tuning to song frequency<br= > </li><li>Active amplification and tuning have an =93on=94 and an =93off=94 = state<br></li><li>Crickets are the phylogenetically oldest insects with act= ive auditory amplification<br></li></ul></div><div><br></div><div><b>Summar= y</b></div> </div><blockquote style=3D"margin:0 0 0 40px;border:none;padding:0px"><div>= <div>A dominant theme of acoustic communication is the partitioning of acou= stic space into exclusive, species-specific niches to enable efficient info= rmation transfer. In insects, acoustic niche partitioning is achieved throu= gh auditory frequency filtering, brought about by the mechanical properties= of their ears [1]. The tuning of the antennal ears of mosquitoes [2] and f= lies [3], however, arises from active amplification, a process similar to t= hat at work in the mammalian cochlea [4]. Yet, the presence of active ampli= fication in the other type of insect ears=97tympanal ears=97has remained un= certain [5]. Here we demonstrate the presence of active amplification and a= daptive tuning in the tympanal ear of a phylogenetically basal insect, a tr= ee cricket. We also show that the tree cricket exploits critical oscillator= -like mechanics, enabling high auditory sensitivity and tuning to conspecif= ic songs. These findings imply that sophisticated auditory mechanisms may h= ave appeared even earlier in the evolution of hearing and acoustic communic= ation than currently appreciated. Our findings also raise the possibility t= hat frequency discrimination and directional hearing in tympanal systems ma= y rely on physiological nonlinearities, in addition to mechanical propertie= s, effectively lifting some of the physical constraints placed on insects b= y their small size [6] and prompting an extensive reexamination of inverteb= rate audition</div> </div><div><br></div></blockquote><blockquote style=3D"margin:0 0 0 40px;bo= rder:none;padding:0px"></blockquote>Best wishes,<br>Natasha<br></div> --047d7bdc11cc0ca87104e794dcda--