I understand this by reading your guide. But when I folow you, sometimes audacity says something like I didn't select any audio. although I still play my selected audio before. Sometimes I have this problem, and Hard to know why. Will practice and describe my work clearly. Thanks for replying ----- Original Message ----- From: David Bailes To: audacity4blind@xxxxxxxxxxxxx Sent: Friday, July 13, 2012 9:51 PM Subject: [audacity4blind] Re: troubleshoot Hi Cuong, In preferences, in the tracks category, there's a check box: select all audio in project if none selected. By default it's checked. For audio to be selected in audacity, one or more tracks have to be selected, and a time range has to be selected. If the above option is checked, then if there are no tracks selected and/or no time range is selected, then if you apply an effect, then it's applied to all the audio. My guess it you have that option checked, and sometimes no tracks are selected, leading to an effect being applied to all the audio. I would recommend unchecking the option. Then if you forget to select a track, nothing happens, and you know that you haven't fully selected any audio. David. ________________________________ From: Dang Manh Cuong <dangmanhcuong@xxxxxxxxx> To: Audacity For Blind <audacity4blind@xxxxxxxxxxxxx> Sent: Friday, 13 July 2012, 15:36 Subject: [audacity4blind] troubleshoot To all listers Sometimes i play a sound in audacity, and mark the selection by the brackets key. I can play that selection, but when i apply effect, Audacity apply to all of the selected track. I think there's something wrong by me, but don't know how to get rid of it. Please help me. Thanks for reading my e-mail. Cuong ________________ Dang Manh Cuong HCMC University of Pedagogy: The Psychology and education Mobile: +84 902-572-300 E-mail: dangmanhcuong@xxxxxxxxx Yahoo! ID: manhcuong0312 Skype name: dangmanhcuong facebook: http://facebook.com/dangmanhcuong Blog: http://vi.netlog.com/Cuong_littlecat Website: http://ngoisaodanduong.com http://www.saomaicenter.org Projec-Website: http://dangmanhcuong.googlecode.com; The audacity4blind web site is at //www.freelists.org/webpage/audacity4blind Subscribe and unsubscribe information, message archives, Audacity keyboard commands, and more... To unsubscribe from audacity4blind, send an email to audacity4blind-request@xxxxxxxxxxxxx with subject line unsubscribe ________________ Dang Manh Cuong HCMC University of Pedagogy: The Psychology and education Mobile: +84 902-572-300 E-mail: dangmanhcuong@xxxxxxxxx Yahoo! ID: manhcuong0312 Skype name: dangmanhcuong facebook: http://facebook.com/dangmanhcuong Blog: http://vi.netlog.com/Cuong_littlecat Website: http://ngoisaodanduong.com http://www.saomaicenter.org Projec-Website: http://dangmanhcuong.googlecode.com