Fiberglass is a good acoustic material!

[sidvee]

Inside one of the strangest looking NASA test sites where sound goes to die

NASA's Auero-Acoustic Propulsion Lab is an anechoic chamber — a room without echoes. Its spiky, fiberglass wedges absorb sound.

us.yahoo.com

If NASA can use it with its multiple PhD scientists and multi billion dollar budget, wonder why this material doesn't make it into humble HT's? However there are reports that it is unsafe for health/ Wonder if NASA people using this facility use masks?
Cheers,
Sid

 

[Analogous]

Inside one of the strangest looking NASA test sites where sound goes to die

NASA's Auero-Acoustic Propulsion Lab is an anechoic chamber — a room without echoes. Its spiky, fiberglass wedges absorb sound.

us.yahoo.com

If NASA can use it with its multiple PhD scientists and multi billion dollar budget, wonder why this material doesn't make it into humble HT's? However there are reports that it is unsafe for health/ Wonder if NASA people using this facility use masks?
Cheers,
Sid

Different materials can be used for acoustic treatment and I am sure fibreglass sheets (embedded in resin?) can be used as well.
it is more important to keep in mind noise reduction coefficient increases with decrease in density and vice versa.
This paper has a table that indicates this for fibre boards (not fibreglass)

Influence of Density on Sound Absorption Coefficient of Fibre Board

For acoustic applications such as theaters, cinema halls, auditoriums the data on acoustic properties i.e. sound absorption coefficient and sound transmission loss are required to evaluate the acoustic behavior of panel products and to facilitate the necessary design computations. Fibre boards...

www.scirp.org

on a side note space exploration industry has anecdotes where humble things like duct tape used for repairs in space. Humans capacity for versatility and jugad is endless It seems.