During Mass on Holy Thursday during the elevation instead of bells I heard a more wooden sound. I was wondering what was going on?
In the Roman Rite, altar bells are not supposed to be rung after the Gloria in the liturgy on the evening of Holy Thursday, and are supposed to remain unused until the Gloria on Holy Saturday. This is supposed to make things more somber as we remember the passion and death of our Lord Jesus Christ.
But, during this short period of time, is anything supposed to take its place? That’s where the crotalus comes in. The Church’s liturgical rubrics don’t prescribe a replacement for altar bells, but there is a long-standing tradition of using a wooden clapper or noise-maker in its place. This serves to both mark the same events as the altar bells, but in a less “sweet” way and thus maintain the somber tone.
More specifically in Paschale Solemnitatis from the Congregation for Divine Worship.
- During the singing of the hymn “Gloria in excelsis,” in accordance with local custom, the bells may be rung but should thereafter remain silent until the “Gloria in excelsis” of the Easter Vigil, unless the conference of bishops or the local ordinary, for a suitable reason, has decided otherwise.  During the same period, the organ and other musical instruments may be used only for the purpose of supporting the singing. 
Or maybe the continuous ringing of the altar bell during the Gloria leaves the bell ringer too tired to do it during the consecration. Well not really.