Does xiang (third tone) mean "want" or "echo"?
響 (xiang3) is the traditional form of 响, which means to "sound" or to "echo". It is not the same character as 想, which means to "think" or to "want". It is not uncommon for different characters to have the same pronunciation and tone. Examples off the top of my head include:


zhong1: 中 (中国), 钟 (两点钟), 终 (终于)
ying1: 应 (应该), 英 (英雄), 鹰
sha1: 杀 (杀死), 沙 (沙滩), 莎
diao4: 调 (调查), 钓 (钓鱼), 吊 (吊着)


Somewhat tangentially, it can be difficult to determine what character a spoken syllable is supposed to correspond to with absolutely no context. One consequence of this is that people often will indicate the characters for their names when speaking by giving examples of terms or phrases with the component characters (e.g. 谢谢的谢，英雄的英). (Character(s) in "given names" rarely form combinations that would be permissible in normal usage, even in cases where a coherent meaning for the whole name is obvious: e.g. 马英九, 崔世安, 周杰伦, 刘博.)